So I've got a new tank set up. In terms of filtration I have an Oase Filtosmart 200 canister. The tank is HEAVILY planted. I added some cardinal tetras, 2 amanos and 1 nerite snail on Saturday. Everything has been fine. It's got cycled filter media and water tests all show safe levels (0 ammonia and nitrite, low nitrates, etc.). So good water quality.
This morning, both amanos were dead and the tetras were gasping at the top for air. Luckily I had an extra air stone on hand and quickly dropped that in. Within about 10 minutes the tetras seemed fine and luckily all have survived (thus far).
Which brings me to my question..... I watch a guy on YouTube (MD Fish Tanks) and he's got a few no filter tanks - nothing in them but plants. No filter, no airstone.... just plants. And his shrimp and small fish do fine. So how does this work? Why aren't his shrimp dying and fish gasping for air? Why isn't the Oase canister filter enough for my heavily planted tank? I just can't figure out why a tank can run with no filtration or airstone and everything in my tank was going to die without an airstone.
Appreciate any thoughts or ideas. Thanks!