I find this interesting. All of my tanks would be considered by most here to be over stocked. I do 20% water changes every 2 to 3 weeks. Yet I only had a nitrate problem once or twice.
Perhaps its the Seachem Stability, or the Safe Start I used to use. They are supposed to have some form of de-nitrifying bacteria.
We use prime. Supposed to de cholorinate, de nitrify, reduce ammonia etc. i dunno if its all that great but so far its been helpful i guess. Only issue we really had was when we had the 10 gallon tank with everyone in it.
I think i would be considered overstocked as well. Hell if i told people what my stock was in the 55 they would probably flip. Atleast the hardcore fish keepers.
Our 29 gallon i think is the i may try the plants in first. Its got 2 gbr's, 2 gourami's, 2 mickey mouse platy's, 2 long fin tetra's, 1 black molly, 1 guppy, and 1 pleco. We use regular sand from petco, and will be mixing their black sand substrate in soon. I think that may also become a ram tank. The tropical fish have become kind of a pain. I just returned 1 gouami today(had 3).
2 weeks ago, we had to fish sit a friends gourami bc her tank had a leak. So until she got the new tank going we kept the flame gourami. We went away for 2 days and came back to find our blue dwarf with popeye. We tried to help it but ended up putting it down. So we figured it was the flame gourami, so we gave it back. So we went and got another blue gourami and they had flame gourami's. So we though heck, try it. Well, it seemed aggressive on the way home ramming the bag, then in the tank it did some chasing. But we let them be. Well, last weekend the gf found my silver molly dieing. So we quarentined in a cup and put it down. Then last night, she found the swordtail dead. So we only had these problems since the flame gourami has been around. Our dwarf has been hiding since we had the flame. So i took the flame back. The new blue comes out more now and the dwarf started coming out a little. But im thinking after we move, startingg the 29 into a ram tank. Possibly trying to find some decent price electric blues. Bolivians, whatever other plants we can find. Planting it as we go.