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ph drop and drop checker

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Hi everyone, I'm curious. My pH is 0 and my GH is 7. My pH is 5.5/5.6 all day. I use CO2 24/7. My pH drop is 1.6/1.7. I degas the water with an air pump for two hours, then I check every hour until the pH becomes stable. Why does the drop control always stay green? Isn't the pH drop high for a 0KH? Should it be yellow? Or am I wrong? Thank you very much.
 

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Hi everyone, I'm curious. My pH is 0 and my GH is 7. My pH is 5.5/5.6 all day. I use CO2 24/7. My pH drop is 1.6/1.7. I degas the water with an air pump for two hours, then I check every hour until the pH becomes stable. Why does the drop control always stay green? Isn't the pH drop high for a 0KH? Should it be yellow? Or am I wrong? Thank you very much.
You said above your pH is 0 but I assume you meant your dKH is 0.

If so my guess is that you are using RO water.

Pure RO fully degassed pH is usually lower than 7.0. Mine is 6.25. And then I drop to 4.85 via CO2 injection.

Just saying your pH drop may not be as large as you think. How are measuring degassed pH?
 
You said above your pH is 0 but I assume you meant your dKH is 0.

If so my guess is that you are using RO water.

Pure RO fully degassed pH is usually lower than 7.0. Mine is 6.25. And then I drop to 4.85 via CO2 injection.

Just saying your pH drop may not be as large as you think. How are measuring degassed pH?
Thank you so much for your reply. Yes, I meant to say 0 KH. Sorry, I take a little aquarium water with a glass, measure for example pH 5.5, turn on the air pump, leave it on for two hours, then after an hour I check the pH and then after an hour I see if the pH has stabilized, I do the comparison and see that I have about 7.2 pH, is the method correct? Thank you so much.
 
I think there is an error in the baseline CO₂ reading you're taking. It's that or maybe your pH meter needs calibration. I recalibrate it before every use.
IMO the drop checker doesn't lie; if it isn't yellow, then you are quite possibly not injecting a 1.5 pH drop worth of CO₂. I have used drop checkers side by side with my pH meter and have found inconsistencies only when my meter was out of calibration or if I contaminated my baseline pH water sample somehow.
I would suggest that you increase the injection rate and wait 1 hour after every adjustment. Keep doing this until you hit a yellow drop checker while ensuring that livestock are comfortable. This way you'll be able to correctly set 50+ ppm of CO₂ even if your pH meter readings are hard to interpret. This is the method I used when I didn't have a pH meter.
 

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