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[Fishology]

I know this ain’t a freshwater website but I couldn’t find any, but I have a 55 freshwater with

pair of angel fish
6 black skirts
5 serape tetras
4 Congo tetras
Two crayfish
And a giant otocinclus that I was gifted,
Today I woke up at saw all the fish gasping for air at the top of the tank. And the oto had died
I have a 270 canister filter on the tank, with hundred of duckweed on top. I don’t know why they’re gasping they should have enough air threw the duckweed, maybe be the duckweed is sucking up the air during the night cuasing them to lose oxygen during the night and early morning. But I don’t know, any help

 

[Timfish]

Obviously low oxygen levels. I would skim off most of the duckweed and add a bubbler or small power head to aggitate the surface. I would also check the canister filter to make sure it's output hasn't slowed down.

 

[Fishology]

Obviously low oxygen levels. I would skim off most of the duckweed and add a bubbler or small power head to aggitate the surface. I would also check the canister filter to make sure its output hasn't slowed down.

Thanks will do

 

[Anemone_Fanatic]

My first thought is oxygen. A bubbler should help, if that's the case. I might also do a test, as a sudden ammonia spike could potentially cause gasping.