Main base atmosphere that plants can grow in?

[Juice]

Before I spend hours piping it up, does anyone know of any limiting factors involved if I were to build the greenhouse with the same air as my base? Every single thing I've read involving mixed base air is somewhere around an 80/20 N2/O2 mix at 101 kPa. And any time I read about plants, they're in a separate, heated, pure CO2 greenhouse (presumably with an O2 filter returning to storage).

But obviously plants on Earth do not need pure CO2, just a small trace. As a unique challenge, could I make an atmosphere safe for mammals that can still grow plants?

I figure I could mix 1 CO2 with 99 O2, then mix that at 22 with 78 N2 to get a 78/21.78/0.22 N2/O2/CO2 mix. That's a significantly higher concentration of CO2 than on Earth, but is it enough for plants in this game at 101 kPa? The only issue I can think of offhand is that the plants will be converting their CO2 to O2 around the clock, while I will not always be around to put CO2 back into the air. The simplest way to fix this I can think of is to constantly draught all the air in from storage, and back out to filtration, which presents additional temperature control issues.

Also is CO2 toxic like X, or does it just displace potential O2, like N2 does? If I determined I need significantly higher concentrations of CO2, could I mix CO2 with N2 first, then mix in O2 at a controlled percentage? Or by that logic, even switch to an O2/CO2 mix?

tl:dr, Any reason why I can't put my greenhouse inside my main base?

[Weyland-Yutani HR]

As long as you get the atmosphere right? I don't see why not.

It just makes filtering a bit more complicated.

[air805ronin]

If it were Earthlike the percentages would be 70% nitrogen, 20% oxygen, and the rest of the contents are usually traces. CO2 usually comes in around .05%.

I've seen a few youtubers successfully grow plants easily with 10% CO2, 10% Nitrogen, and the rest Oxygen.

I'm about to try to do this with my base with an expansion. Probably be able to finish the expansion this weekend. I currently have a mix of 15% CO2, 15% N, and 70% O. I don't know where we'd get the Nitrogen to make an Earthlike mix, you'd make SOOOO much oxygen by melting oxite. I guess you'd never need to worry about filling air tanks...

[Weyland-Yutani HR]

I've found that ferns create a crazy amount of O2 just by themselves. Even a single plant would create enough oxygen for you to keep your suit stocked.

[Buzzzz]

This is what I'm running and it works as a Human and plant habitat. 70 o2, 20n2 and 10 co2. Would run more N2, but I dont have enough.

[Juice]

Originally posted by air805ronin:

I don't know where we'd get the Nitrogen to make an Earthlike mix, you'd make SOOOO much oxygen by melting oxite.

It's pretty difficult without exploiting the furnace/ore behavior. I'm hoping that if they change it, they wait until after they've added a better source of nitrogen.

I think my mix design should work. I may need tweak the numbers until I can get the CO2 levels just right so that the plants don't starve themselves. I still need to sketch out where and how to keep enough atmosphere mix without letting the mixers burst a pipe. Also decide where to run A/C.

[Weyland-Yutani HR]

Has anyone tried adding CO2 to the plants water supply to see what happens?

[Bunyan]

Originally posted by Buzz313TH:

This is what I'm running and it works as a Human and plant habitat. 70 o2, 20n2 and 10 co2. Would run more N2, but I dont have enough.

I used to run this until a spark blew up my base...that oxygen-rich is great for breathing, but not for fires.

I switched to a 10% CO2, 40%N, and 50% O2....seems to work quite well so far. I'm not totally convinced yet though...still watching and maybe tweaking it.

[VegasGoat]

I made an area that was 70% N, 26% O2, and 2% CO2. It purposely doesn't add up to 100% because I'm using logic that turns on pumps for each gas individually when it falls below the desired percentage, or when the pressure is below 105. Basically, mixing the gas in the room rather than before in the pipes. I can take off my suit and grow plants in the same area.

[Kraft51]

Originally posted by VegasGoat:

I made an area that was 70% N, 26% O2, and 2% CO2. It purposely doesn't add up to 100% because I'm using logic that turns on pumps for each gas individually when it falls below the desired percentage, or when the pressure is below 105. Basically, mixing the gas in the room rather than before in the pipes. I can take off my suit and grow plants in the same area.

this is the most accurate atmo ratio so far. it seems the majority is convinced that more O2 is a good thing :) ... especially considering your numbers only add up to 98%, accomodating the fact that we don't have Argon, Neon, Ozone and a myriad of other trace elements that are present in our atmo amongst the CO2 traces. IRL ratios are around N2 78% and O2 21%, the other elements present are so minute that they aren't really a factor other than the missing mass.

keeping your O2 down below 25% is the best way to ensure unforseen base fires :D
anyways thats my opinion on the matter lol.

[Juice]

Originally posted by VegasGoat:

I'm using logic that turns on pumps for each gas individually when it falls below the desired percentage, or when the pressure is below 105. Basically, mixing the gas in the room rather than before in the pipes. I can take off my suit and grow plants in the same area.

I didn't think about doing that. Sounds like a good idea though. Would solve the issue of the plants starving themselves.

[GD]

There are four major problematic things about that.

(1) Plants needs sunlight, so placing them anywere but the roof with full of glases reduces their effectivness to 50% mostly even less. And having too much windows increases your temperature problem.

(2) Having rich O2 environments >50 is dangerous. If by accident somewhere somehow you have a H2 leak and a heater or a Welder just on "On" your hole base gonna light up. So if you want that anyway I would recommend using real air/mixed air. Which makes a good filtration system and mixture system necesarry.

(3) To avoid having too high percentage O2 mix air you need N2 and a lot of them and currently there is no real good way to get it in large quantities.

(4) Sunlight increases the airs temperature as well as any electric device. The plants are rather sensitive to temperature changes. Below 15 or too hot and they not just wither, they disappear within 3 minuts or so and you need to reseed everything. So a very effective temperature control is required and no accidents, e.g. Furnace having thermal contact to your bases air or something like that. Too cold gases in your pipes cooling off everything. A lump of oxide or ice accidentally dropped ... so much can happen.

Minor additions

(5) You need water for them. So everywhere you intend to plant plants you need a water connection and enough water. Ice is somewhat rare on the maps and even if you have some you must watch out for its temperature it can cool or heat the rooms as well.

-----

I also thought about it, but made a little test-area for that first and noticed the immense problems you start facing that. But reviewing the problems I'm a little hesitent to go that way. I often thing also about Mark Whatney from the movie, just one Airlock Failure and all his plants gone to hell and you know how easily you can oversee something and accidentally vent your station during construction.

[William the Bat]

I am thinking chickens would be a good source of CO2 to keep your plants alive - but I can't say I've tried it. In a stable system, it would have the advantage of not relying on how much smelting you are doing and having your plants die because you are debugging your electronics or something. Hmm, is there an optimum chicken-to-plant ratio? I think I'll have to melt a whole lot of oxite to have enough N2 for a stable, non-dangerous atmo. And emergency backpressure vent-to-vaccume on the oxy tanks while getting it. I think for your pressured living envrironment regulating gasses individually is probably the best bet, as there are just so many things that can go wrong depending on what is going on in the habitat.

[Kraft51]

@GD ... silicon and lead actually produce a decent amount of N2 during the smelting process.

http://steamcommunity.com/sharedfiles/filedetails/?id=1249509687

heres a chart someone has put together showing gas production ratios during the smelting process.

[GD]

Thanks I'm well aware and already made the Gas charts myself twice. I'm also aware of a certain procedure to get even more gas at least for the time being. Still, to fill your base with 70% N2 as part of your mixed Air you need a lot of mols for that. Depending on your bases size a lot more than the 6000 l / 25000 mol you can pack into a Small Tank.

One advantage however remains. When you have it it can stay in the circulation system. You only need to balance the CO2 and O2 contentration and of course everything that don't belong in there like H2 and X.

[Kraft51]

yes i realize this, i was just pointing out there are various ways to aquire N2 :)