How Much Co2 Actually

fitos100

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May 17, 2019
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hi. I read to many sites the rule of 1 point of PH corresponds to 30ppm of CO2. If in my tank which I have 8 PH and 4 KH start to inject CO2, I will get 30ppm at the 7 PH or i will get 30 ppm to 6.6 PH as the chart of PH/KH/CO2???
 

fitos100

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May 17, 2019
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yes my friend, but I'm confused because from 8 Ph I go until 6.2 with no problem. (I try to see my co2 limits). How is this possible??
 

fitos100

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May 17, 2019
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Every day I start inject Co2, 2 hours before my photo period and I stop 1 hour before the lights are off. The Ph before I start inject Co2 daily goes do 7.4 ( not my final Ph ) with the help of agitation, so my target Ph Drop is from 7.4 Ph?? If it's like this it's make sense.
 

Phishless

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Degassed would be your highest pH number.

Many have tried a higher CO2 drop 2.0+
I'm sure there's a limit where CO2 becomes wasteful without further growth improvement.
 

Joleena

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Aug 26, 2017
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I have a similar question. Prior to adding CO2 my pH was 8.2. After beginning CO2 (with my reg at mid-level SPB) my pH came down to 8.0 for several days. I increased my regulator to a higher level of SPB and it came down to 7.6 over a couple days (or rather it came down in ~24 hours and I gave it an extra day), made another final adjustment to the maximum output of my regulator and the pH has been stable at 7.6 in the AM when everything comes on (CO2 comes on 1 hour prior to lights) and then by mid-afternoon pH is 7.2
Am I reaching 30ppm CO2 if my starting pH was 8.2 and I reach 7.2 daily? Or am I likely short on CO2 if my morning pH is 7.6?
Should I degas a sample and get a new reading on my "starting" pH?
Also, with my current level of injection being the maximum output of my regulator, if I am NOT reaching 25+ppm CO2...what would my next best step be?
 

Phishless

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Also, with my current level of injection being the maximum output of my regulator, if I am NOT reaching 25+ppm CO2...what would my next best step be?

My regulator delivers 7 PSI that feeds three tanks, all have a CO2 reactor and @ least a 1.2 pH drop is in all three tanks.

What is your method for CO2 injection?
 

Tom Barr

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1 st real rule is watch the plants ressponse and the livestock. You can very slowly increase the cO2 rates each day or week and watch closely. At some point, you will reach the end point where addign more does no good or you gas the livestock. A clean surface and good flow help add O2, which offsets high CO2 ppm somewhat with livestock and bacteria. I typically degass the water for a few days. Then I'll do say a 1.2 pH drop and watch and if possible, use a data logging pH meter. This way you can see what it does all day while "on". Or if you are around all day and can note the readings, that works too. Generally the faster the climb up to the set point, the better. But...you do not want it to go above that set point either. Generally it does not. Degassing plays some role here and the 1st law of diffusion(Fick's law) does as well. Itll keep climbing if you have a scum layer on the water's surface and less movement on the surface. Do not do that. Remove the scum at all cost. After 1.2 pH drop is good, I'll adjust very slowly upwards and watch live stock and shrimp etc. If everything looks great and dandy, I'm good. Hard to know what that looks like when you are new though.............
 

Joleena

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That was an excellent and thorough response, thank you.
I feel like I am on track. I feel confident that I can read my livestock sufficiently to dial in a stopping point.
What is your definition of "adjust very slowly upwards"? Daily adjustments? Weekly adjustments? By PSI? Based on plant response? Are there too many variables to quantify this?
What is your definition of "fast climb to the set point"? Within an hour? Within 10 minutes? Is this too dependent on volume and other factors to be able to quantify this?
Thank you again.