Let me just give my full set up. 55 gallon tank with standard stock lighting. Filtration includes a Fluval 305, a Top Fin 30 ha-on filter (I keep the water level high to minimize agitation, and it is on the opposite side from my CO2), and a fluval 3 internal filter. My temperature is about 79-80 degrees, with hard neutral water. Hardness and nitrates are both kind of high.
My plants and mosses include: 1 amazon sword, a few java ferns, moss balls, anubias coffeelia, anubias nana (medium and large), nana petite, crinum calistratum and other onions, a reddish ludwigia plant, anacharis, sagitteria, java moss (which doesn't seem to grow completely over the drfitwood for some reason) and red tiger lotus. Sorry for the spellings.
My fish and invertebrates include: 4 Mystery snails, 2 clown loaches, 1 Red Finned Shark, 1 Gold Nugget Pleco, 13 Black Neons, 1 Dwarf Rainbow (his 2 mates died in the past few days; I also lost a betta and 2 angel rams), 2 German rams, and 4 otos.
OK...1 rainbow had a bacterial infection, which spread to and killed my betta, after it killed the original host. I dosed the tank three times with tetracycline TC (I believe that was the name), yet I did not remove carbon. I have been adding garlic, and I did a 20 percent water change today. Another rainbow died from what looked like ich (may have been cotton wooly, like the others - hard to see). I raised the temperature and added garlic. I am not seeing any other signs on fish, but I am concerned. My water parameters have not changed. I was so exscited when I added my latest batch of plants a few weeks ago, but my stocking the tank with 3 rainbows, 2 angel rams, and 1 betta has threatened my tank and killed all but one of the new arrivals. It's frustrating, and I worry that I am not out of the woods yet. The only real positive is that I have minimal algae growth if any....lol.