Ok, tank parameters are 0.0 of all amonia / nitrate / nitrite. PH is 7.4. Tank is about 5 months old.
77 degrees (heated obviously) and weekly 15% water changes despite perfect parameters.
It houses 6 female bettas and 8 zebra danios, 29 gallons. 6 live plants taking up about 25% of the tank, and a piece of real driftwood which takes up about 10% of the tank.
I recently bought 5 oto cats, having done a lot of research on them - I went to two separate pet stores, and hand picked each one - larger, defined black stripe, no discoloration and round bellied.
I have a brown algea bloom, as well as the white fungus on the driftwood that all otos supposedly love. I figured now would be the perfect time for them.
One by one over the past two weeks they have died. Usually about 3 days apart. From what I can tell, they arent eating. I've put blanched zucchini, potato, and romaine lettuce in there - as well as hakari algae wafers. They have not touched *anything* I haven't once seen them on any of the above (they will hang out on top of the potato and zucchini, but never eat it) i've never seen them eat the algae or the driftwood fungus. They hang on the filter sometimes, and the glass - but lately just hang out on the driftwood doing nothing.
I'm down to one otto, and I can't figure out whats wrong. Obviously the tank is more then suitable for them. Any suggestions would be great.