# Co2 adjustment for correct amounts



## elkhunter (May 24, 2012)

How do you go about maintaning 15-20ppm I have a 29 gallon tank I just got my Co2 and everything setup now im trying to adjust flowrates and stuff to attain what Im trying to establish as a correct value of 15-20ppm in my water I have 4-24Watt bulbs running for about 9 hrs total and 11hrs if you include the 2 hr break for the algae. Will 1 or 2 bubbles per minute attain this value thanks. BTW running PPS pro for about a week now.


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## elkhunter (May 24, 2012)

BTW I think my PH is like 7.2 or so and my KH looks like its about 3 dGH or 53.7ppm


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## jseyfert3 (Apr 9, 2012)

Each tank is different, so if you're aiming for a specific CO2 level then you need a drop checker. Filled with 4 dKH solution, it'll be green at about 30 ppm.

Lots of places sell 4 dKH solution, as 30 ppm is the level the EI method says to use. To make your own solution for your 20 ppm target, get some RO or DI water and baking soda and use this calculator: http://dropcheck.petalphile.com/

Two drop checkers can improve accuracy, and the author of the calculator (wet) talks about that in his thread here: http://www.aquaticplantcentral.com/...s/69633-one-drop-checker-good-two-better.html


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## elkhunter (May 24, 2012)

Ok thanks yeah I ordered a drop checker so when that gets here i will set it up is 30ppm a better spot for me to achieve?


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## jseyfert3 (Apr 9, 2012)

elkhunter said:


> Ok thanks yeah I ordered a drop checker so when that gets here i will set it up is 30ppm a better spot for me to achieve?


I haven't got my first tank going yet, plants are in the mail. So I'm not really the one to ask. On the site for PPS though, they say:


> A good target to start is 1 bps (bubble per second) for medium size aquariums which is simple to do and safe to fish and sufficient to plants. Maintaining 10 ppm under low light will increase plant health significantly. Maintaining about 20 ppm under medium and high light is more desirable to provide sufficient Carbon for the plants. Exceeding levels of 30 ppm doesn't allow much of a safety margin.


https://sites.google.com/site/aquaticplantfertilizer/home/co2-injection

The EI directions I will be using to start with say 30 ppm. But that's not the method you're using. Also, from stuff I've read, I've seen values from below 20 all the way up to like 45 or so. So I guess my suggestion is to start where your directions say is a good starting point and tweak it from there as you get feedback from the plants (and fish?) and do more research.


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## elkhunter (May 24, 2012)

My tank from yesterday when I did my measurments when from 7.2 to 6.2 and dropped one degree in KH and my fish are sucking air from the top so i aimed my canister outlet flow to the top of the water surface instead of blowing into the water column cause i could see small bubbles of Co2 floating on the surface of the water. So i tried turning down my co2 i thought i was roughly 2 bpm. 
What should I do will turning the outlet towards the surface be enough to keep the co2 at 2bpm or should I keep the outlet up and keep the bubble count down farther?


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## jseyfert3 (Apr 9, 2012)

elkhunter said:


> My tank from yesterday when I did my measurments when from 7.2 to 6.2 and dropped one degree in KH and my fish are sucking air from the top so i aimed my canister outlet flow to the top of the water surface instead of blowing into the water column cause i could see small bubbles of Co2 floating on the surface of the water. So i tried turning down my co2 i thought i was roughly 2 bpm.
> What should I do will turning the outlet towards the surface be enough to keep the co2 at 2bpm or should I keep the outlet up and keep the bubble count down farther?


A bps (bubble per second) is an arbitrary measurement unit. It's really only good, AFAIK, to adjust the CO2 in _your_ tank. I.e. a visual representation of how fast the CO2 is coming out, so you can turn your needle valve and see how much you slowed down or sped up the output. It doesn't actually mean how much might end up in the tank, because plants will use some, more or less will be lost via gas exchange at the surface, and if you don't have 100% absorption, not everything that passes through is getting in the water.

So, no, aiming the output at the surface will not reduce bpm, but it probably will reduce ppm, a measurement of how much CO2 is in the water, by increasing surface agitation and therefore gas exchange and so more CO2 will escape.

But that's kinda backwards, if you want less CO2 in the water, slow down the needle valve. Why would you want to slow the needle valve vs more surface agitation? Because if you have to increase surface agitation and therefore CO2 loss from the tank, that's extra CO2 you're loosing, and you'll have to refill faster then if you didn't increase surface agitation but slowed down the needle valve.

From what I've read, if the fish are affected, you've got too much CO2 in the water. (Somewhere over 40 ppm, I think).

BTW, how are you diffusing the CO2?


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## elkhunter (May 24, 2012)

No I did both slowed down the needle valve and created more surface agitation at the same time. I was asking if keeping the CO2 valve at its initial rate while having surface agitation would be good or if I should just reduce Co2 and not mess with the output.

If i calculated it correctly i had like 38ppm of Co2
Im diffusing using a ceramic diffuser

My Co2 tank is a 10# aluminum tank with a aquatek deluxe with solenoid valve regulator and a plastic check valve half way down the line with Co2 resistant tubing that came with the regulator.


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## jseyfert3 (Apr 9, 2012)

elkhunter said:


> No I did both slowed down the needle valve and created more surface agitation at the same time. I was asking if keeping the CO2 valve at its initial rate while having surface agitation would be good or if I should just reduce Co2 and not mess with the output.


Myself, I would try reducing the CO2 valve without messing with the output and see how that works first.


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## elkhunter (May 24, 2012)

Well I left the Co2 on the surface and put my Co2 at like 2bps again and I came home from work and the KH was 3 degrees and the PH was 6.6 so left me with 24ppm which I think is pretty good! So I will monitor and see if it stays stable.


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## Yo-han (Oct 15, 2010)

Don't fixate on calculated numbers. Besides the fact that they are quite off usually, it all depends on what the plants need. Your plants tell best if you've enough and your fish and shrimp tell you if it is too much.


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## elkhunter (May 24, 2012)

Thanks im waiting on a Co2 dropper so check on it and also I know it was too high the other day and now it seems fine the plants are growing so im assuming its alright


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