Planted Tank Guru
Join Date: Nov 2009
Location: Missouri united states
With apisto's, I would not be too worried bout how much peat to use, but might would have wanted it mixed into the soil beforehand.
Not to say placing some in the filter, or cutting source water with R/O will not bring desired result's , but might take some experimenting with to get right %. (in a bucket,tub)
If tank was not too large,,I might consider re-do with pure sphagnum peat mixed with soil.
Seem's is what I must do to keep some of the soft water species due to fairly hard water.