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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. This suggestion is very specific to your circumstance.
 
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Sounds like your tank is similar to mine. 0 dKH , GH 6. Degassed pH = 7.3. Right now, as I am still dialing in the outflow on the Yugang reactor , I am hitting equilibrium between 5.8-5.9 pH. This evening at pH 5.9, the Hanna CO2 titration is reading 37.5 ppm at end titration with a barely visible pink color. My drop checker is also green, so if going for a higher level of 50-70 ppm, you probably aren't there yet. It is my understanding that the 1.0 pH drop rule doesn't apply to tanks with KH < 1.0, but someone else here can correct me if I'm mistaken. My question is, how accurate is the Hanna titration in these tanks, and what should the actual target ppm be (presuming one needs to keep the levels safe for livestock)?
 
Sounds like your tank is similar to mine. 0 dKH, GH 6. Degassed pH = 7.3. Right now, as I am still dialing in the outflow on the Yugang reactor, I am hitting equilibrium between 5.8-5.9 pH. This evening at pH 5.9, the Hanna CO2 titration is reading 37.5 ppm at end titration with a barely visible pink color. My drop checker is also green, so if going for a higher level of 50-70 ppm, you probably aren't there yet. It is my understanding that the 1.0 pH drop rule doesn't apply to tanks with KH < 1.0, but someone else here can correct me if I'm mistaken. My question is, how accurate is the Hanna titration in these tanks, and what should the actual target ppm be (presuming one needs to keep the levels safe for livestock)?
I would also like to know the answer to this question. I'm also running a 0 dKH tank with injected CO₂ and use the Hanna CO₂ test kit. @Naturescapes_Rocco has mentioned that when he compared the Hanna kit against an OxyGuard CO₂ meter, he found the Hanna tended to read about 5–10 ppm higher at 0 dKH. At 1 dKH the difference was closer to 0–5 ppm, and around 2–5/6 dKH the Hanna was pretty much spot on with the OxyGuard.

I'm curious if anyone else has done similar testing or has more information on how accurate the Hanna titration is specifically at 0 dKH. I'm currently using it alongside my pH curve rather than relying on either method alone, but it would be interesting to know how much other acids/buffers present in a 0 KH planted tank could potentially influence the Hanna result.
 
I would also like to know the answer to this question. I'm also running a 0 dKH tank with injected CO₂ and use the Hanna CO₂ test kit. @Naturescapes_Rocco has mentioned that when he compared the Hanna kit against an OxyGuard CO₂ meter, he found the Hanna tended to read about 5–10 ppm higher at 0 dKH. At 1 dKH the difference was closer to 0–5 ppm, and around 2–5/6 dKH the Hanna was pretty much spot on with the OxyGuard.

I'm curious if anyone else has done similar testing or has more information on how accurate the Hanna titration is specifically at 0 dKH. I'm currently using it alongside my pH curve rather than relying on either method alone, but it would be interesting to know how much other acids/buffers present in a 0 KH planted tank could potentially influence the Hanna result.
I can at least chime in and say that carbonic acids, the type that are produced when CO2 is dissolved in water, is by far the primary chemical species in our aquariums influencing pH. At low KH (low carbonates already) our pH pens and Hanna kit might not be as accurate, but still, the carbonic acids are 90-95% of the types of acids present. If you're using aquasoil with lots of decaying driftwood or leaves, maybe the humic acids would have some effect.

But, primarily, you can definitely trust the readings you're getting with pH drop or Hanna test kits. The more important thing isn't the difference between 40-50ppm in your tank, but having truly stable CO2 that starts plenty early enough to saturate the water column for the entire photoperiod. Which it sounds like you're getting dialed in!
 
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