What's wrong with my tetras?😓😱?

I went on holiday for 5 days and before I went a put a 5 day tetra food stick in their tank. They also had no light for 5 days as I don't have a timer and I obv couldn't leave their light on for 5 days.
When I got back home a few mins ago all 5 of my tetras where swimming very close to the bottom, and hiding in there tunnel, the has NEVER hid before, even when I first got them. They are also very pale, the blue&red hardly visible, they just look a kind of peachy/whitey colour.
What's wrong with them?
(I have turned the light on now and they haven't perked up)

Megan ❤2015-05-27T17:05:15Z

Assuming they're neon tetras their color get's very pale when the tank is dark. And the light being off will also cause them to be less active.

How big is your tank?
Do you have a heater?
Do you have a filter?

Answering those questions and I'll be able to give you a better answer.

?2015-05-27T18:32:44Z

Probably that "feeder" of yours is poisoning the fish. It lets off ammonia which is toxic.

Do a 25% water change now, a 50% water change an hour later, and another 50% water change an hour after that.

The fish would have been better off without a feeding block. They won't die if you don't feed them, they can find algae to eat and are made to go long periods of time without food.

noselessman2015-05-27T19:31:08Z

Those vacation feeders are terrible. It is a pile of junk food incased in some plaster of paris or weird unnatural jell. The casing melts into the water, then the fish gorge themselves till they are sick on the junk food.

Fish are fine for 5 days without food. any longer than that and I would look into an auto feeder.

Have you tested the water for ammonia, nitrite and nitrate?

Do wultiple partial water changes to get the reults back to
zero ammonia, zero nitrite and nitrate not over 20.

Fast the fish for a few days and feed them very sparingly for a while.