Did a 60% water change on Sunday and haven't added anything except recommended dose of Flourish. Here's what is going on:
pH seems to have returned to its prior levels, generally hovering around 6.8. Tap water pH seems to be changing as well; from 8.0 to 7.6. GH is 3 degrees, and KH was 3 all week long but this morning is measured at 1!
This is really helping me zero in on some issues. I read that plants with use CO3 in the absence of CO2 and that this can cause diminishing KH. That does seem to be my problem. After a water change my KH is at 3, but after a few days it sinks to 1. GH stays at 3.
So, my question is what to do? Should I supply Excel as a CO3 source for my plants? They apparently aren't getting enough carbon to grow as they wish...
I provide CO2 but at a very low rate (about 3 bps).
Maybe this should be a new thread, but since it is
a follow-up of my old problem I left it here for the convenience of those interested in helping me out. Appreciate any advice. I have 6 nerite snails and more plants (4 Echinodorus, 8 E. tenellus, 3 pennywort, 3 Althernanthera roseafolia) on the way so I'm trying to get these issues squared away. Thanks in advance!