Discus fry tank heater choice

[chippy]

Do you have a heater guard on that 100 watt yet? Unguarded glass gets hot spots fry can touch. My 30 gallon fry tank uses 50 watt guarded sub, bare bottom, sponge filter, 83F, powder food three times daily, 20 percent changes three times weekly. Without guard I lost a few two week olds that parked on the tube. Horizontal placement under outflow fixed the corner cold zone more than adding wattage.

[mirus]

I would recommend verifying temperature at multiple points before selecting inline versus submersible configuration. In my experience with a forty gallon bare bottom nursery using sponge filtration alone, placing a seventy five watt unit horizontally beneath the return flow produced more uniform readings than heating the surrounding room. Water changes of thirty percent twice weekly should utilize pre conditioned water at identical temperature. Fry receiving powder food four times daily remain sensitive to fluctuations exceeding two degrees Fahrenheit within short intervals.

[raid]

Half setting sounds safer but I still do not trust submersibles with fry that small on bare bottom. One stuck thermostat and you lose the whole clutch. I lost twelve three week olds after a heater overshot overnight in a 30 gallon sponge filter tank on powder food, 82F target, 25 percent changes. Maybe run two smaller units instead of one 100 watt so a single failure does not wipe them. Corner temps worry me too, 79F is a big gap.