• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up
  • You can now follow UKAPS on Instagram.

Drop checker PH test confusion


6 Jul 2008
London, UK
I'm having trouble understanding my new CO2 system. :?
I set it up as the big book says but something just isn't right. I'm using a drop checker with the 4dKH and the Hagen PH test kit, adding about 2 bps of CO2 and the checker seems to be all right. It's green-ish. But when I check the PH of the water it the results always way over 7.0. Around 7.6 - 7.8, bright blue!!
If I'm right the PH should be around 7 when the solution is green in the dc.
The KH is around 8.
I'm confused. Should I increase the bps or just ignore the ph test and wait to see what happens? :arghh:
Any ideas?

Ed Seeley

3 Jul 2007
The pH of your drop checker is totally independant of the pH of your tank. That's why they are so useful at measuring the CO2 concentration as that and the KH are all that effect the colour of the pH test solution.

If you're injecting 30ppm CO2 it should drop your pH by about 1 degree from wherever it started, so, assuming you are at 30ppm CO2, you must have started with a pH of around 8.6. Check your tank's pH in the morning before the CO2 goes on and then again in the evening before it goes off to see the changes and check what's happening, but at the end of the day you don't need to worry about the pH of your tank unless you want to keep fish or plants that like water of a specific pH.

Similar threads