Join Date: Jan 2003
Location: Fort Collins, Colorado
I figured out at least part of my problem: my substrate was killing my plants.
I pulled the wood from the tank, and when I did, a dark cloud rolled up into the water column from beneath it - it looked nasty and smelled just as bad, so I pulled all the plants around it to turn over the substrate to try and fix the situation. When I did that, I saw that every part of every plant that was beneath the surface of the substrate had turned black and begun to melt/rot. I started pulling everything else out - all the same. Black roots, melting stems, etc.
Anyway, I turned over the entire substrate - rinsing it several times - trimmed a lot off each plant, and reset the tank. My guess is that as I added fertilizers, the plants couldn't use them since they were getting poisoned (more or less) by the anaerobic gunk in the substrate, so algae went nuts, further damaging the already decaying plants. So, big build-up of nitrates.
I also found my Seachem Nitrate test kit and compared it with the AP test - Seachem read 0 ppm when I finished a 90+% water change (which is normal), while AP read 10 ppm. So, looks like AP's is just a crappy test kit.
Walker of the world's weird wall.