I've had my tank setup now for about a year, and four months ago I experienced a major crash with all my plants. Throughout this time I've been dosing Flourish and Excel per recommended dosing, but started dosing dry ferts given the issue at-hand. For purposes of this discussion, I have had four or five categories of plants: Anuibus, dwarf sag/val, lotus, alt mini, and swords. My lighting is probably considered medium, and my substrate consists of black diamond blasting media and eco-complete. I've also been placing osmocote plus capsules periodically, especially in the vals and swords. What I'm assuming has happened is my plants had been thriving on the eco-complete, and when those nutrients depleted the plants crashed. In the past four months I've been playing catchup trying to get a dosing regimen that would maintain 20-40 ppm nitrates. It seems like the more I dose the faster my "tank" is consuming them. I'm literally putting in heaping tablespoon of KNO3 every other day now, and my nitrates jump up to 40-60 ppm, then are zero by day two. Based on my research for a 125 gallon aquarium, this is A LOT! At this dosage my plants are rebounding SLOWLY, but something seems to be consuming nitrates at a ridiculous rate. I had two canister filters plus a 29 gallon sump for filtration, but have recently removed one canister filter to see what happens. The anuibus grew very slowly the first 8 months, probably due to under fertilization, but everything else exploded with the exception of alt mini which I cannot keep alive. The first plants to show signs of the crash were the dwarf sag, then the vals, lotus, and swords followed in that order. Then I started dosing dry ferts, namely KNO3, but also K2SO4 and KpPO4 at times. The sag were the first to rebound, and the anuibus have been growing like crazy. I can see the vals and lotus trying to rebound, but they are nowhere near their former glory. The two sword plants have basically just stalled out.
I guess my question is, is this a normal amount of dosing for a low tech tank given the plant list and lighting? It seems like something about my setup is consuming crazy amounts of nitrate. Link to my setup is here for reference, but no current pics since it's sorta sad to look at. https://www.plantedtank.net/forums/1...l#post11258317