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Sumps and successful CO2 injection methods

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20 Dec 2019
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South Carolina
As the title implies, I’m looking for those of you running sump setups to show how your injecting and how long it takes to reach that sweet spot of 30ppm+. I really enjoy my sump, but I’m finding getting the CO2 high enough without being wasteful is difficult. Thanks!
 

zozo

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The 30ppm idea is a max safety threshold for the livestock and giving as much as possible to the plants. It doesn't necessarily mean your plants can not thrive with less. I did read quite some success stories from people with large tanks and sumps administering 15ppm CO² only 24/7. And stated that this was much easier to maintain stability without wasting too much CO².
 

Mr.Shenanagins

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Flow rate through the sump is not quick by any means with my two sponge barriers. I do not have typical baffles, the sponges act as baffles and mechanical filtration. In between I have floss and lava rock. Don’t need it but it’s an extra buffer for biological filtration. The reactor is right above the pump input. I’m contemplating figuring out a way to seal it, but the wires and plumbing make that difficult!
708CAACF-2E83-451A-80FF-882E1388CB73.jpeg
 

tiger15

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Do a search on Tom Barr who designed many sump systems with CO2. I recall seeing pic of injecting CO2 into a sealed chamber to prevent off gassing thereby turning it into a self contained reactor.

I agree it is not necessary to reach 30 ppm CO2 as a performance goal as it is really a safety threshold for the life stock. Most plants will do well below the threshold and there is a greater margin of safety to protect livestock in case of accidental over shooting. I have stopped measuring CO2 target for a long time and rely mainly on observing plant growth.
 

ceg4048

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As the title implies, I’m looking for those of you running sump setups to show how your injecting and how long it takes to reach that sweet spot of 30ppm+. I really enjoy my sump, but I’m finding getting the CO2 high enough without being wasteful is difficult. Thanks!
Hello,
CO2 application is wasteful by definition, so you'll really need to get over that aspect of it. Only about 10% of what we inject actually makes it into the plant beds. The rest evaporates into thin air. A simple ceramic diffuser ported into the inlet of the return pump is really all that is necessary, or you can port the gas into the tank's inlet.
The sump should be kept covered to help retard escape.
This doesn't need to be complicated at all:
16270949749_93fef4be76_c.jpg


Cheers,
 

tiger15

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If you have an open top tank, you will lose more CO2 to vaporization than in a glass top tank. I have read posts that reported 50% reduction in CO2 loss by monitoring ambient CO2 levels around tank top under covered condition. So the concern for CO2 loss in the sump may not be as consequential as loss in an open top tank.
 

Mr.Shenanagins

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Thanks for all these replies. I understand that most of what is injected is wasted, I’m just looking for the most efficient way possible (despite how inefficient it is in the first place!). I think I may just end up getting one of those bazooka style diffusers and put it right in front of my pump. For extra diffusion I could just add it to my reactor for even finer dissolution I’d assume.
 

Michael1212

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This might be of interest My 200g window

The atomizer + reactor combination lead to 100% dissolution quickly, which I think you are after if you want to be efficient with co2 usage. My tap water is 7.2 ph, kh 1, and over 3 hours this setup is now dropping my ph down to 5.7 - 5.8. My sump is turning over > 4000 L / hour, I don't believe I'm using an obscene amount of co2, but I've been running only 2 weeks so far, so I shall wait and see.

I agree that an open tank seems to lose far more gas than a sump. Sealing my sump with plastic wrap did nothing for me, but one day when my tank had some surface film I observed ph drop much faster.
 

Mr.Shenanagins

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Interesting. Right now I have a bazooka style diffuser in my reactor and while it’s working well, I’m getting lots of gas buildup in the reactor. I’m contemplating just putting the diffuser right at the pump intake instead of the reactor. I’m also considering a needle wheel pump that exits right at the return as well.
 

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