This advise you may be helpful throughout the game.

To help with economy, try to learn what building use what materials. A very good example here would be managing food. Your food factories require Ice and Chemicals. Polymer Factories also use Chemicals. If you are low on Chemicals, you may want to turn you Polymer Factories off to make sure that you have enough food or prioritize the Food Factories.

You will encounter some "Do I do or Do I not" dialog when talking to yourself after being asked a question. This will normally add a new Directive. They seem to me like side missions. They will add to the story, but not necessary to complete to continue the game even if you do accept them.

There are many areas that you will get a flood zone warning. In a lot of these areas, it is okay to build. They really don't get flooded unless you import a lot of ice from off planet. Once water starts to build and you can see water standing, you will get an idea of what areas are going to actually flood. Using the color to tell the height will help as well. Most of these zones are locked to start with anyway.

Not counting the food to support your population, Steel is going to be your most used resources throughout the game. So you will be wanting multiple factories. Some projects may not seem like they need Steel, but it is an underlying resource. Example is projects that need Parts. You need Steel to manufacture Parts.

Research Outpost are useful as long as you can keep the people site supplied with resources. Once you complete the research project at the site, they will give your research a percentage boost as long as they are populated. I don't know if the game really says this directly. You will see that is mentions a percentage when looking at the current research projects status.

Hyper Loops and Advanced Landing Pads will be your best friend. Once you have the research points at a sufficient rate, I would invest in getting them researched.

The Hyper Loops will allow you to connect your bases around the planet. Once you have a main Hyper Loop Terminal build, They do have a max distance that they can be built for them still being able to connect. As long as there is a connection line, you can tell if they are within reach of each other. When you have a location decided, place the next Hyper Loop Terminal. You then need to place the Advanced Landing Site close enough to connection the the Terminal as it contains enough resources to build the Terminal. The actual Steal and Carbon that are needed to build the connection will be coming from the other side. I will note that if you try to build anything before the Hyper Loop Terminal, you won't have the resources for the terminal. Also note that they need to be Advanced Landing Pads. Regular Landing Pads don't have enough resources.

When build Ports, you need to remember the the game will treat the body of water like one big road. So if you have ports at 2 different bases that are connected to the same body of water, your ships will transport resources from one base's Port to the the other. If you are using the water to gather resources, this can be a distraction for your ships as they transport resources rather than collect.

I don't normally use Storage Centers. I only research Extra Storage research for the ability to manage storage of my Landing Pads. I like to reserve space for food and Steel. I normally try to have normal Landing Pads built and on stand by ahead of time. I do this because Landing Pads have the same amount of storage space. They also both generate power and come with their own drone. I will also note that since it is a Landing Pad, it will bring some of the resources that you spent on it coming back with it. So even though it seems to cost more, it comes back with a lot of the resources spent. It really only cost you the Parts and Chemicals. You get back 20 of the 21 Steel that you spent and since it also acts like a worker hub, you get back more in steel than you spent.

The start is pretty straight forward as you will just need to follow the directives as they are basically a tutorial. You just need to be prepared and look at requirement as it will tell you to build a certain structures, but will unlock multiple buildings. An example would be that it will tell you to build a Polymer Factory, but it won't tell you to build a Chemical mine. You need the Chemical Mine to create Polymer. You will have also built yourself an Archaeology Scanner or 2 to search for new resources.

You are now ready to begin preparing for the Colonist.

I don't think that it tells you, but you will need to build an Ice Mine then the Food Factory. Once that is done, you will need to build a Colony and a Space Port. The order that you build is up to you.

Once the Space Port is when the colonist will start on their way. So if you build the Space Port first, you can build the Colony while they are on there way. If you build the Colony first, you will have a little time to make more resources before they arrive.

While the Colonist were on their way, you will probably have found a research site to build an outpost on. The site seems to be different per game. So you may have found it by scanner or just built a structure close enough for it to appear. So you will want to build the research outpost there. I will have want to build a second Colony the second load arrives.

Now the colonist have arrived and research can begin. You can now let your Space Port transporting Colonist set as a repeatable Project.

This is where the terraforming missions truly begin. You will be given the task of getting the Temperature to be about -50 C and get the Frozen Co2 below 5 mbars. There are basically 3 options to easily complete this task. 2 of the 3 come from research.

To do this you will need to start the research projects.

The first 2 that you will want to research are Additional Landing Sites and the S-01 to let you build more Space Ports. I would Suggest S-01 as it will give you time to build the Space Port while you research the Additional Landing Sites.

I assume by this point that you will have received a directive to build a second base.

The third thing that you will want to research is E-01 to increase the maximum amount of buildings that you can have. This is important to be able to build that second base.

You will most likely have completed the E-01 research while you were working on building the Additional Landing Site and launching the satellite to unlock the new Sector. You will have wanted at this point started doing research on B-01 to increase your maximum Colonist count. Once B-01 research is complete, I suggest researching Advanced Colonies.

Once the new sector is open, you will need to drop your landing site and build a second base. This process will be similar to when you started the game as you will need to build all of the structures and factories again. The main difference will be that you are also able to do research and build the economy of your main base.

During this period, you will have to make the big decision on how you are going to deal will the Frozen CO2 to complete the terraforming objective of getting it below 5 mbars. You can choose researching Black Polar Dust, Space Mirror Array, or use the option that you found by following the directive. If you choose to one of the research options, don't waste time researching the other. Don't research either if you choose the directive option. You can use those points to focus on other research. NOTE: If you are going for Achievements, each option has its own achievement. So you may play through the game 3 times.

Once you have finished Advanced Colony research, your next research project will depend on how you plan to melt the Frozen CO2.

You will have some time to research. I would suggest Fission Plants so that you can start mining Uranium. I would suggest Wind Farms as well as they should be quick to research. I would suggest NOT researching the Green House Gas Factory. I would hold off on the Water Supply Factory as there probably isn't any water yet. You can probably hold off on Battery research depending on how you play. I don't find myself using them that much.

So you will probably want to go for Advanced Mines and/or Superior Colonies depending on your current population.

I would then go with S-03 and research at least one of the 4 Space research options to help you start increasing the temperature. These seem to be more efficient in heating the planet that using the Green House Gas Factory which is why I skip the research. Although whatever project you chose will normally release the CO2 to cause you to reach your -50 C temperature goal. The next stage will want you to continue to raise the temperature. This will have you ready for that step. Although GHG Importation will probably be the most important one as you will want to go up that as it is a requirement for research the ability to import Ice and definitely Nitrogen in the future.

During that period, you will probably have built a third Space Port and upgraded your Colonies to Advanced or Superior as well as built a second food factory.

At this point, you can basically research as you want as you are basically at a point where you will be gathering the part for the projects and maintaining your economy until the next stage of terraforming.

The following are my suggestions to do as we wait.

I would say to avoid researching the Greenhouse Gas Factory and the other projects that are not needed as I said before. I would also say hold off on researching the Carbonate Nuclear Extraction as you will probably want to avoid building that. You will only need to research it in the future to get to the Nitrate Nuclear Extraction.

For me, I will normally try to get the Roads and Advanced Landing Sites researched. Depending on how far I am away from completing the releasing the Frozen CO2, I may consider researching E-03 so that I can start researching Hyper Loops.

You will now have reached Stage 2. You now have to raise the pressure above 300 mbars.

This is done by raising the planets temperature. Your some of your choices from Stage 1 will carry over and continue increasing the temperature for stage 2.

I will note on this play through of writing this guide. I chose to use Solar Mirrors.

Other than a few actions, the temperature was raising on its own. I mainly focused improving my research and economy. I worked to get my population above 1000 if not higher. Just make sure that you can provide for their needs.

You probably won't be doing much at your secondary base other than maintain supplying your research station. Although you can probably build a Space Port there if you wanted.

I would try to focus on research at this point. Other than the story, they stage almost completes itself The research will include the new Military Research Tree that opens up.

You are half way to reaching the 300 mbars goal. I assume that you will probably have all research trees to level X-02 now. Since most Biotech research involves that there be water on the planet, you probably don't need to research anything in the B-02 tree but only did it to increase your population Cap. The only new things under Biotech research will be water related. Water won't start appearing until the next Stage. So you can hold off on those.

You will want to have had at least completed all research projects for M-01 and at least M-02 for the additional drones.

You will probably have wanted all of the S-02 research projects completed except Comet Disintegration. I would suggest that Advanced Landing Sites be an early one so that you can get at least 2 produced. Although you won't be launching yet.

Your completed Engineering research could be a bit mixed depending on what you spent time doing research at the end of the last Stage. Now is a good time to research S-03 so that you can research Hyper Loops. This may be a long project depending on your current population, but will pay off in future time saved and resources. It will also let your bases share resources.

At this point, new areas in the world will be opening and you will want to expand. By completing the Hyper Loop research, you won't need to build out full bases like you did for your second base. You will just need to place your Hyper Loop Terminals where you want them then place the Advanced Landing Pad within connection range of Hyper Loop Terminal. The Advanced Landing Pad will have the resources needed to build the Hyper Loop Terminal as long as you don't build any other structures first. Once the Hyper Loop is complete, you can get those resources from your main base. This is where researching the Hyper Loop early will save you time and resources.

Note: You may have read that dropping a Landing Pad will make extra resources appear. This seems to be true as long as you don't drop the Landing Pad an area that has been scanned by your Archaeological Scanner. So try dropping in areas that haven't been scanned. This is something to take into consideration when determine the drop point of building Hyper Loops.

So back to terraforming. You basically just need to follow the story and continue researching. This stage will almost complete itself. Although you may want to through in a helping hand every once in a while, but I didn't have to do much until the end.

We are now at Stage 3. You goal are the following:
Get above 0 C
Have a water level of more than 400 m
Have more then 1 mbar of O2

Depending out much you helps speed up Stage 2 can effect what all research that you have done.

You really won't be working on the 1 mbar until the end as you will need water. You will need to build structures close to the water and you will want water at a steady level before building near it. As you can guess, builds get destroyed if left in water.

If you haven't finished Hyper Loop Research, then do that. If you haven't researched Advance Factories yet, I would suggest doing them next.

The primary factories that you will probably want to update is Food, Steel, and Worker Factories. Like I would avoid upgrading your Parts Factories as it would draining of you Steel.

Once done there work on the B-02 Structures that require water. So that Oxygen Release Plant is not needed right now as it takes the same resources as food and it can cause risk for future stages.

I would suggest that you focus on BioTech Research. So that you are ready when the water reaches it goal. As the Temp goes up, the Ice deposits will melt and slowly fill the planet with water. You can get to your goal faster by researching the Space Tree for Import Inc and Aerobraking Ice Asteroids. Using those 2 projects will help you reach the target goal faster but will bring in extra water so that there will be a higher water level overall. You will want them researched from being requirements for the next level. How much you use them is up to you. You will be wanting to build Water Treatment Plants and Aqua Domes, which require that they are near water. You may drown them as the water rises.

You may want to put some research into upgrading your Military Tree as well. Everything will probably be at X-03 at this point. I would suggest getting all of M-03 Researched with the exception of Advanced Assault Drone Factories. It may just be better to build an additional factory than spend the research points on it now.

You can probably leave the Engineering Tree alone for now unless you need to increase your building cap. Superior Mines may sound helpful but really aren't unless you have found mines that Require you to have Superior Mines. They are rare and hard to find, especially on harder difficulties.

Once your water level has become steady, you may will want to look into increasing your population for faster research. With water steady, you will be easier to build Water Treatment plants to start providing water to the required buildings. You will probably be building multiple Water Treatment plants to provide enough. This is a part where you are going to have to make some decisions on how you are going to manage your population.

The questions that you have to decide on is what you are going to do with the water and craters.
Do you build Dome Colonies to help increase your population as they only require that you be connected to a water supply but you only need to provide them with food? Dome Colonies will probably be a temporary solution until you can start building Tent Cities.
Do you build Crater Farms, which all you need is a water source and they generate food?
Do you make Water Packing Plants, which will produce Ice? Games suggest that this counters the melting ice. Meaning that it slows the raising water level. This means that you would probably be using Superior Colonies to increase your population.
Do you build Animal Sanctuaries in your craters to help boost research speed?

Once you have that all decided and researched, I will suggest 2 options depending on you research points coming in. If you are still trying to boost your population, go back to Engineering Tree. Make sure Aquatic Structures are researched and then try to research Nitrate Nuclear Extraction. You will need to research Carbonate Nuclear Extraction first. Do B-04 and research Bioengineered Animals. This will allow you to build Fisheries.

Those decision will determine what research that you do in X-03. If you get all of that done in Stage 3, I would suggest working on the Items in S-04 as they will be required in the coming stages.

Now back to the basic Terraforming. First goal is to get your Temp above 0 C. Importing GHG and Aerobraking Methane Asteroids are going to be your main way of heating the planet which in turn will melt the Ice an start getting the water to show up. That is pretty straight forward there. Just a bit time consuming.

Note: I am not sure how the melting Ice and rising water mechanic works. It says that Melting Ice will raise the water level and Water Packing Plants will do the opposite. You will probably need a lot of Water Packing Plants to do something. I build a couple and the water continues to rise. I believe that it is only effected by Ice that is lost by Melting. I don't think it counts if you mined it. If you notice all of the Ice Veins are gone, the water probably won't be raising much more on its own.

You should can clearly see that the lake to the south of your main base is starting to contain water. It seems to fill up quick while you might see spots on that big ocean area. While this is going on, you can expand east. With Hyper Loops now researched and if you built those Advanced Landing Pads ahead of time, you should be able to start working your way east to find locations to build more Research Outpost and find new resources. I normally let all of the resources go back to my main base for me rather than build new factories. The Hyper Loops will allow your main base to provide Worker Drones to any new Worker Hubs. If you haven't, now would be a good time to research Extra Storage for the ability for Storage Center Management. It will be quick research since it is E-00 level. I hardly use Storage Center building, but that is a different story described at the top section. Now that you are building these new Research Outpost, it will be useful to make sure that your Landing Pads have open storage for Food and Ice for the outpost.

The resources to the north of you main base are optional. I would move to your east to get the research sites first, Most of the northern resource will get flooded. You will also need to work on building more Advanced Landing Pads to do this. So it will take time. You can try to take a shot and see if you can make a profit before the area becomes submerged. I haven't tried as I also need to be aware of my Building Cap.

Work on setting up the new sites while you try to raise the Temp. You will probably be doing this by Importing GHG. I normally get it to around 10 - 15 C to get the water stable. I would think that this would probably stabilize the water level as you will probably have used most on the planet.

We need to get the water to a point where it is over 400 m and not quickly rising. I aimed to reach my target Temp between 10 - 15 C. I had reached 250 m for my water level by the time that I hit 10 C. The Ice veins were still in melting status, so that water would continue rising, During this period, I was working on Directives and advancing my research. I didn't do the Import Ice from Europa or the Aerobraking Ice Asteroid research right away but did some of the other Military and the Biotech research that was needed for plant life, but you could do either order. I just focused on one so that I didn't go through my resources too fast as both importing Ice and Importing GHG uses the same resources. Although they are different amounts. You will also need Space Ports available for each one. I have 5 Space Ports at this time, 1 of those is transporting Colonist. Leaving only 4 for the other projects.

Continuing on from the last section.

Now while you research and Import the ice and GHG, we will expand and make preparations to start the increasing O2 once we are at a good water level. We previously working to expand Eastward. We will want to move that way to be able to gather resources and build a few more research outpost. I would avoid putting a research outpost on the Curiosity Rover side as that small area will flood. So you would have started 2 additional bases going east.

The second will probably be on the border of what the game labels as a Flood Zone. It normally doesn't flood unless you bring in a lot of water. So you should be ok to build. To the north of this base you will see what kind looks like it will turn into an Island.

You will want to start working on setting up a new base there by using another Hyper Loop. I will just call this an Island base even though it won't become an Island. The west side of the side is where you will see the water will rise. So get a base started here.

Now we will just need to get the water to rise to our 400 m goal. We will actually want it to go higher. We want the crater area on the east side of you main base to flood. So we will need to go passed that 400 m. You will probably being wanting it around 550 m. That will fill the crater and giver you an opening to the ocean as well. Even if you try to stop at 550 m, There is still probably Ice melting, so the water will still slowly rise.

After that 400 m water level, this Island base will allow us to start O2 production easier than other areas without getting flooded too quickly. You will now want to build an Aquadome or 2 next to the water. This will slowly cause the O2 level to rise and we will work our way to the 1 mbar. These 2 Aquadomes will slowly start the O2 but won't be quick on their own. You can also probably build a Water Treatment Plant and Water Packing Plant to start producing your own Ice.

With the Water Treatment Plants, you will also be able to use that water to support the Biodomes. The Biodomes will acted just like the Aquadomes except for land. You will want to build the Biodomes at the edge of your bases as building block plant growth.

I will note that you will probably have to deconstruct and rebuild the Aquadomes as water level rise as the old one may get to close to the water level. Also, the plants life won't really spread beyond the radius of the Aquadome until the next Stage which is why you will need more than 1. The same spread all relates to the Biodomes, but they still produce O2.

Like I said, we will want to get the water level to around 550. Once you reach the 400 m, build 2 Aquadomes to the West of you Island Base to start producing O2. Once you are around 500 m, I would try to have at least 2 Water Treatment Plants and to start using Water Packing Plants to slow the waters rising. It will still rise and you may even want to import a bit more Ice. If my understanding is that any water that is melted from Ice Veins will increase the water level, I have been aiming to try to put mines on them as you will mine some of the Ice before it melts and raises the water level.

One of the things to do while waiting is work on expanding your Water Supply Network with Water Booster Pumps. They have a version large radius. So you should probably be able to connect them between bases if you build them on the side of your base. This will allow all of your other bases not close to the ocean to have water. This will let you build the Water Packing Plants closer to your building that need Ice rather than have them use up some Hyper Loop traffic. You can also build Biodomes at other locations.

Remember that you only need their ranges to cross even the slightest. You don't need to build them inside another pumps range.

I believe that some of this upcoming part will require the Blue Mars DLC. You can also build Water Booster Pumps and Water Treatment Plants on the water once you can build Ports. You can probably build Ports by this points. The would probably get flooded and destroyed due to water still rising. But you can connect them with other Bases that are near water even if they haven't reached the shore to to Water Booster Pumps long range.

We are doing this while we waiting are trying to stabilize the water rising at around 550 m. O2 should also be increasing due to the Aquadomes. With the Water Network going, you can probably build a extra Biodome or 2. You won't want many until the level is stable as you will need to build more Water Treatment Plants. We are preparing to be ready to boost O2 production more and increase the Population and research speed.

So we now have a fairly stable water level and the crater next to the main base is full of water. By now you will have wanted to have researched Bioengineered Animals.We want to be able to build Fisheries. Having research Dome Colony and/or Tent City will be helpful.

So to start, I would suggest start by building 2 Ports and a Shipyard. You should now be able to build Fisheries for additional food and at least 2 Research Outpost maybe more depending on water level. Now you can build Fisheries and bring in food easily. I would definitely try to get those Research Outpost built as once populated will give you 10% research boost. A single fishery can feed them. Those Research Outpost, even though on water, will also need to be connected to a water supply network as they require 5 ML. So you will need to build at least 1 Water Treatment Plant as they provide 40 ML. You can connect them using a Water Booster Pump or a second Water Treatment Plant. Either way you will want a Water Booster Pump so that you can connect that extra water to you water supply network on land.

You can now be able to build any Colonist Building and feed them easily. You just need to make sure that you have the water available in your water network or the Ice available if it is Superior Colonies. Just make sure that you have worker drones available to transport the food. Also, Ports act like mini Storage Centers but can only hold 100 resources. Switch them to Custom mode and set it so that it always has room for food. Your ships may not pick up the food otherwise as your Ports are full.

As a Warning, if you build Ports at your main Base and your Island Base, the ships will treat the Ocean as a big road and transport resources between your bases. This may distract them from gathering food. It you do build in both locations, make sure that you mark food as high priority or they may just ignore them. You will also want a lot more Ports. So I would suggest against it. The only other Ports that I will suggest is in the lake south of your main base once it unlocks as that water doesn't connect to any other Ports.

With that ability to increase the amount of colonist that you can maintain, will help boost your research.

You can build another Aquadome in this area and another BIodomes in other areas to help speed up the increase to reach that 02 to the 1 mbar. Then just wait and expand your population.

I will assume that you have Tent City researched. Suggested research during this period would suggest all research in the S-04 chain, especially the Space Elevator to bring in colonist in larger amounts at once. You will also want to do Organic Material Dumpster and Nitrate Nuclear Extraction. I would also look into getting Oxygen Capture Plant last out of that list. That will require you to complete the Oxygen Release Plant first. This is all to prepare for the next Stage.

The rest of the Research in the game is really up to you. But I would suggest E-04 for the building cap increase and do some Military Tree research to improve your drones. Once your Research Point income is good, researching Fusion Power for the big energy boost and it makes it easier to connect all of you base energy grids. Open City research can wait as you can't use it until Stage 5 anyway.

I believe that this requires to Blue Mars DLC. But now that you have an Ocean and Ports, I thought that I would create a section on how to use this to your advantage. I thought that I would explain it here rather than explain it as I go along. If you don't have the DLC you will probably have to deal with Farms.

The biggest advantage that I found was that you have a large area to make food production a lot easier. You can keep building Fisheries as long as you have the resources. They are smaller than the large farms and require no input other than needing to be built on water. Even being built on water is an advantage as it leaves you more room on land to build. The only complication is that you will need to have enough worker drones ready to collect the food. So you main need to build additional Storage, a Landing Pad would be best because of its own worker drone and/or have a Hyper Loop ready to move them elsewhere. Upgraded Roads are also good to have to help the worker drones move faster as these areas can get very busy. Note: Watch worker drone movement and you will get an idea of the path that they take and where to build the roads.

Always remember to Customize your Port Storage so that there is a minimum food requirement.

Even though other bases may not have ports, you can still connect your other base's power networks by using Wind Farms that are on the water. The same goes for the water supply network using Water Booster Pumps. Even if the base isn't real close to water, you can put the building right next to land and it can reach farther in. All you need to do is cross the others radius to connect. You only need to make sure that they are covered by a Maintenance Facility.

You can also use this to build multiple Water Treatment Plants and not take up space on land.

Even though these buildings make be far from your Port, your ships should need to visit them once they are built as they don't need input or will you need to collect resources from them. The only exception is the Maintenance Facilities to be able to replace repair drones and that doesn't need to be done often. I normally have at least 5 ports, so a ship or 2 wondering off to take them resources for a replacement, is not a big deal.

You now have reached 1 mbar of O2.

Your next goal is to get O2 to be above 120 mbars and keep the O2 Percentage below 30%.

This will be someone simpler than reaching the 1 mbar as your Biodomes and and Aquadomes will start spreading beyond their small radius as long as none of your roads or buildings block the expansion path.You will find the most growth in the high humidity areas. You can determine those by using the humidity view filter. The biodome filter will help give you an idea too. Pretty much every area that was labeled as a Flood Zone will get plants growing.

You can really remove all but 1 Aquadome as that is all that it will take to fill the Ocean. You will need 1 other to fill the lake as it is a separate body of water. It won't be as fast but it will still occur. No need to rush either as you need to make sure that you keep the O2 level below 30%. As the game suggests you can use Nitrogen as a buffer. So hopefully you at least researched the ability to Import Nitrogen.

Hopefully by this point you have had time to research and build a Space Elevator, set up a good food supply from Fisheries, as well as have had time to research and build a few Tent Cities. The Space Elevator will allow you to fill those cities quickly. You will want to be building at least 1 more Space Elevator during this Stage, but don't need to right away as they cost a lot of Carbon. Just be prepared as Tent Cities cost 200 MW of power. This will give your research a nice boost. I have just started Stage 4. I have over 6000 Colonist. I also have 12 Research Outpost. Some of those are from story the others were just sites that were near the points where I made my bases where I made Hyper Loops. 5 of those are near your main base, 2 on land and 3 in the water. Build a few Animal Sanctuaries and you have doubled your research points.

During this Stage, the Lake to the South of your main base will have been unlocked. I would suggest starting a base down on the East side of the Lake. You will have access to 2 additional research project sites and large amount of resources should be here. You will also be able to access the Water for another area to build fisheries and not overload your main base.

From here it is build Biodomes in high humidity areas. The plants will grow as long as they are not blocked by buildings. You can pretty much just focus on growing your population some, research, and directives. The plants spreading will do the rest. You just need to wait. Although you do need to bring in Nitrogen occasionally to keep the O2 below 30%. This is one reason that I suggested against using Oxygen Release Plants.

We are now at Stage 5. The Goal is to get CO2 level below 5% while keeping O2 below 30%. You will also be required to build a Magnetosphere. For this, you will have needed to complete the research for a Magnetic Dipole Sphere.

This stage will require a lot of Parts and Electronics. You may want to set Priority to 1 Steel Factory, 1 Electronics Factory and 1 Parts Factory. I say Steel as it is a requirement for Parts.

By this point, you will have most likely finish most research projects except those X-06. This probably depends on population and how many Animal Sanctuaries that you have. I really only find the need to research S-06 and B-06. You want the B-06 for the remaining research projects. S-06 for the repeatable Space Improvement research. With B-06 you there is the Atmospheric Humidifier and the other being Urban Floral Integration.

You probably researched Open Cities. You can't populate them until you complete Stage 5.

I like to do a 1 or 2 loops for the Space Improvement research as your remaining projects in Space are reduced in cost.

For Urban Floral Integration, you buildings no longer block plant growth and the Atmospheric Humidifier will let you make plants grown in new areas on where they are built. Once those are done just do the Space Improvement research. You can do others as well. You shouldn't have to worry about completing any more military research.

You should mainly focus on getting the the CO2 below 5%, but also keeping the O2 below 30%. This is the reason that I suggested not build Oxygen Release Plants and Carbonite Nuclear Extractors. The Oxygen Release Plants would make it harder to keep that percentage below 30%, which means that you would need more Nitrogen to off set the additional O2 that you added. The Carbonite Nuclear Extractors would mean more CO2 that you would need to remove.

Hopefully you had been Importing or generating Nitrogen during the last Stage to help make this quicker. There was the 3 research options to go for. Nitrate Nuclear Extractor, Aerobraking Nitrogen Asteroids, or Importing Nitrogen. Importing is the most reliable. The Asteroid brings more in than importing but are rare and Nitrate Extractors require you to find Nitrate Mineral Veins to build on and the resource does run out. Last play through, I only found 1 Nitrate Vein previous play, I found a bunch.

Using those 3 Methods, you need to make sure that the O2 stays under 30%.

You can just wait it out and let the plants do all of the work on turning the CO2 into O2. To speed it up, it is easiest to build Organic Material Dumpsters near areas with large amounts of Trees, even better if there is a Biodome nearby. The Organic Material Dumpster will remove a small amount of the trees and convert CO2 into O2. The trees will regrow over time, but faster if near a Biodome.

The basic concept here is that you are converting the CO2 percentage into O2 percentage. The Nitrogen will need to technically cover that other 71% in the case that CO2 reached 0%.

If you need to lower the O2 percentage, you can also use Oxygen Capture Plants. This could technically cause the CO2 percentage to increase because nothing is replacing that O2. You still need to keep the O2 above 120 mbars. The Dumpster are still converting the CO2 into O2. So the CO2 is still decreasing. I would suggest doing this as a backup in the case that you can't get Nitrogen in fast enough to keep O2 below 30%.

While we are waiting for that, now is the time to work on building the Magnetic Dipole Shield. This is the reason that I said that you may want more than one Space Elevator. Only Space Elevator can complete Magnetic Dipole Shield projects. You will need to complete this project 15 times and it cost a lot of iron. Depending on how much Iron that you have stashed away, will depend on how fast much you run this Project. If you got plenty, then just loop the project. If you are short, just do a piece here and there as you are still trying to lower the CO2 percentage.

That is pretty much all that there is to this stage.

While you are waiting for this stage, I would suggest increasing your food production for the next stage. You can do this by creating more fisheries. If you need more spots to build Open Farms, you can use the Atmospheric Humidifiers to open additional areas to build. You may also want to increase your power and connecting all of your power networks. You may also want to build another Space Elevator if you have the resources.

Congratulations Mars is Terraformed. Now there is the Home DLC.

After the Credits, it will bring you back to finish the Home DLC. Now that Mars is livable, you just need to populate it. There are 4 Objectives. Get Flora Level to 50%. Have 5 Open Cities. Have 5 Open Farms, and reach 50000 Populations.

Flora probably reach 50% during the last Stage. You may have also built the 5 Open Farms last Stage. You could have build the 5 Cities they wouldn't work do to lack of breathable atmosphere.

So this is pretty straight forward. Hopefully you have more than 1 Space Elevator. You will set all of your Space Elevators to Migrate Colonist projects. That is like 2000 Colonist per trip. You can start those before building your cities.

You will need to make sure that you have 100 ML water available and 2000 MW of power to maintain all 5 Cities. This does not count resources to maintain your farms. You will just need to make sure that you have enough food production to feed everyone. If you have Blue DLC, I suggest additional Fisheries otherwise you will probably need more Farms.

Technically this all could have been done during Stage 5. You would just need to complete the step to migrate the Colonist. You just give all of your Space Ports and Space Elevators the job of migrating colonist then wait or prepare more food while you wait. You probably Max game speed if you haven't.