Overdosing CO2?

Ian H

Guru Class Expert
Jan 24, 2005
265
0
16
Shipley, West Yorkshire, UK
I've just got an API KH test kit and used it to test my temporary hardness..........The result was 10 degrees. This was a bit of a shock as my KH is normally much lower. I re-tested with my Interpet kit and got a value of 5.

I tested my tapwater and got 3 on the API and 1.5 (on a 10cc/2 basis) on the Interpet. It's quite soft water here. I decided to add 1tsp of bicarb to 17.2 litres of tapwater which I estimated should give me 13 degrees in total on the API test, ( I based my calculations on a value of 1.1tsp in 50 US gals giving 1 degree hardness) Could you check my figures here please Tom or Greg?

I got a result of 15 (API) and 8 (Interpet). I considered the API to be the more accurate.

This has left me with a bit of a problem as my PH is between 6.6 and 6.8 and a calculated CO2 level of between 48 and 75 ppm..too high. I've reduced the bubble count to 1 every 2 secs and intend to do a 25% water change to reduce the carbonate levels. By the way the fish are OK.

Just a warning to all I suppose, my CO2 strategy was based on a KH result that was wildly inaccurate.

Ian