Co2 drop checker not changing colour!

[aibo82]

Hi

I set up my co2 in a rio 125 and im using a AE glass drop checker with hagen ph test and premixed 4dkh but when I dose co2 its refusing to turn green!

it started off as deep blue now its going lighter blue but no green just clearer in colour!

Ive never had a problem befor could it be the 4dkh solution is off it it 8 months old? also ive changed my substrate to colombo florabase so my ph is sitting lower in my tank at 6.8 at the moment!

Any ideas?

 

[Dolly Sprint 16v]

The problem might be that the hagen ph solution may not be compatible in indicating Co2 levels within the water column. I will admit that I do not know much about the hagen ph test solution, the co2 my be affecting the solution and that why it turns clear especially when the co2 levels are increasing (Co2 entering / being mixed within the water column.

JBL do a co2 reagent Inc. ph solution - but its main use is for indicating Co2 levels not ph levels.

Regardspaul.