As part of my new discus tank build i decided to build a DIY pH monitor, I have included it in my journal but I don't get a lot of traffic. Anyhow using my electrical engineering student ability (first time it's been useful in the real world) I programmed an Arduino to monitor pH and calibrated using pH4 and 7 solutions. LCD screen came today so I could finally un tether it from my computer and get it in the tank. Result.

I know it's accurate because water comes out of our tap at exactly pH 7, the kit color matches up perfectly and we are close to the water processing plant and they say on their side they aim for neutral output. Also there is drift wood in the tank which may have led to the slight drop.

On a side note 6.95 appropriate for discus if acclimatised or conditioning required?