Fish Suddenly Hide - All The Time

[dasjman]

Background: I've had aquariums for probably 20 years now. Currently have a 50 gallon bow front with some real rock, and quite a few fake plants (silk ones) bordering the back of the tank.

This tank currently has about six Black Skirt Tetras, one remaining neon tetra (from an original group of 10) that is almost three years old now, one remaining Black Phantom Tetra (from an original group of six) that is also about three years old, and five gold barbs. Also one green cory.

All have been in the current tank together for quite some time, and have always been active. Starting about six weeks ago, they all started hiding in the plants, except the one neon, who cruises around everywhere. They now only come out when the tank is dark, and will scramble for cover if the tank light is on and anyone comes near.

I've changed nothing about the tank, the lighting, etc. Any ideas why they have all gone into witness protection all of the sudden? And help, ideas, or advice welcome, and thanks!

 

[FreshyFresh]

Welcome to the site! What's your water change schedule and amount of water changed? Do you have a means to measure for ammonia, nitrite and nitrate? We generally try to eliminate a water quality concern first.

 

[dasjman]

Welcome to the site! What's your water change schedule and amount of water changed? Do you have a means to measure for ammonia, nitrite and nitrate? We generally try to eliminate a water quality concern first.

Water is all good. Also, the fish all seem to come out when it's dark. If the tank light is off and it's relatively dark in the living room, they are all out and about. It's really weird. They used to be out all the time, but now they all just hide in the plants in the back of the tank if the aquarium light is on, and if they do happen to be out, they all scramble in a panic if you walk near the tank. Nothing different about the light either.

 

[FreshyFresh]

I'm not trying to be a snot, but "water is all good" means absolutely nothing without readings in PPM for ammonia, nitrite and nitrate. A healthy, established tank should produce nothing but nitrates and we keep them ideally below 20ppm by doing weekly water changes. Just trying to rule out a water quality concern which is the cause of most concerns.