so i recently added 3 albino corys to my 55 planted, and they seem to be spending alot more time in the upper region of the tank, they will swim down to the bottom of the tank and then shoot up to the top almost like they wanna jump out especially when the lights are off. my water is crystal ammo is 0 nitrate and nitrite are 0 ph is a little high at 7.4
Anyone else had this happen to them before? you think they are stressed
Yeah I would go with the oxygen idea... If they continue add a bubbler or something to aerate or better oxygenate your tank. One time at a LPS I saw a 12" pleco swimming to the top and gasping for air out of the water. It was insane, and sad.
I would say that they are stressed. Cory are schooling fish and 3 isn't enough. Especially in a large tank. I have False Julii and Panda, and they group/school/eat together almost all of the time. If they are anxious or fearful for their safety (there's safety in numbers, so say schooling fish), they may stay near the top because they have to get a breath of air fairly frequently. If they go to the bottom, where they are when behaving normally, they must shoot up for the air and if there aren't enough of them they may feel vulnerable to predators when they do that, so they hang out at the top.
A fantastic site for all types of Cory and any information you ever wanted on them is www.planetcatfish.com.
Oh, and they are *notorious* jumpers and will jump out of a tank when they are perfectly content, so they will definitely fly when anxious. Cover that tank.
The Cory sites recommend a *minimum* of 6, but I would seriously consider at least 8 for such a large tank. Really. They'll be much more fun to watch too! Mine are a kick. Send the old lady to me.....I'll convince her. :)
Ask her if she would be opposed to you bringing in a few potted plants into the house, maybe for the kitchen area. When she says ok, just present the tank as a big pot.....
ok everyone....this is the old lady...(as i'm now referred to thirty years before i should be.) more fish is ok the 20 gallon potted tank..no. but anyone is welcome to come over and convince me otherwise :)