KH 5dkh but ph at 6.6?

[bclee]

I suggest that you try to find what the "co2 level" is from the chart before you inject. After you inject co2, check the level again. Do the difference...that should give you the actual co2. Assuming all being equal.

Logically, I think that would work....

No it doesn't work. You can't use the chart at all.

BC

[PeterGwee]

Use the chart as a guide but you are not bound to it. If plant growth (aka pearling via O2 splitting from H2O) is sub-standard add a bit more CO2 and see if things improve. If not add a bit more and so on as suggested by BC till the point where the critters act funny and then back off. You need to make sure that the light and nutrients are good during the period of adjustment or else you will and can kill your critters.

Consider some riccia tied to a rock or driftwood and see if it pearls 2-6hrs into the photoperiod. It should pearl well if the nutrients and CO2 are good.

Regards
Peter Gwee