20 Gallon Tank My Cardinal Tetras randomly stopped eating flakes

I'm using the same type of flakes I've had for the last 6-12 months. My Cardinal Tetras used to go CRAZY for them and eat them all in seconds. Now, the last 3-4 times I fed the flakes, they only nibble on them a little but and then mostly ignore them -- and some flakes remain uneaten.

The only two foods I feed are pellets, and flakes.
Any idea why they are no longer interested in flakes? Seems like they still eat the pellets aggressively.

 

What’s the expiration date? Maybe they’re no longer good and the fish are letting you know

Also even if within the date moisture and opening could shorten the life

 

What’s the expiration date? Maybe they’re no longer good and the fish are letting you know

Also even if within the date moisture and opening could shorten the life

I was thinking the same thing. I've had fish stop eating food that had got old or stale.

 

Think it has to do with the fact that they aren't surfacefeeders but midwaterfeeders. They probably feel more safe to feed on the pellets.

 

Or, it could be a sign that they're being fed plenty and just not that hungry.. so they wait for their favorite. I've seen this before.

 

Might try to fast them for one day every now and then and see if they eat what ever you give the next day like the flakes.. Might be overfeeding when your fish become selective or just that the food is gone bad.

Overfeeding can cause algae issues and bloating or other sickness on fish in the long run so doesn't hurt to try.

My tetras sometimes ravage my floater roots if im away for a weekend like they were "so starving" haha.

 

You can put the flakes in a cup of tank water and use a turkey baster to get them below the surface. I used to do this.