Hiding danio. Any ideas?

[Squiffy]

10 gallon tank
Ammonia/nitrite: 0
Nitrate: 20
Age of tank: 3 months
Contents: 5 danios, 4 ghost shrimp, 2 mystery snails, and a handful of fry that i can't catch to remove

One of my danios has taken to hiding inside the castle in the tank for the past week. I only see him/her during feedings. There's nothing visibly wrong with the fish and when it is feeding it swims normally and doesn't seem like anything is wrong. I haven't added or removed anything from the tank and the fish have all been in there since the cycle completed 2 months ago. Any ideas why he's hiding?

My tanks seem to be an ideal breeding ground because every time i look at it there seems to be new fry. I'm doing water changes every other day to keep up with the levels until I'm able to catch them and put them in my other tank that is less populated and where i usually hold the fry before going to the lfs.

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[Luananeko]

What kind of danio? It's possible the one that's hiding is getting picked on by the others. Most danio species get bored and have pent up energy when kept in a 10g tank. This tends to lead them to be a bit nasty to the bottom fish on the pecking order, especially when kept in smaller schools (less than 7 or 8+ members).

Zebra & Leopard Danios in particular are prone to this, and really do much better with at least 30" of tank length to burn off their energy.

 

[BBradbury]

Keeping Danios

Hello Sq...

Danios are very active, shoaling fish and are comfortable in a group of 8 or more, so a larger, heavily planted tank is needed. A 20 gallon is probably the minimum. Fish in small tanks can be stressed and act differently.

You'll likely get an opposite opinion, but I keep Rosey Danios and have them in a larger tank. Danios are hardy fish, so they may adapt to a different environment.

B

 

[mPhish]

One time one of my guppies hid in a corner nearly motionless for almost a day. I asked people here and got the idea that something spooked him, or as someone said above me, that he was being picked on. I'm pretty sure my thermometer scared him, it floats around occasionally. Check if the filter or a bubbler or a floating thermometer could have spooked him.