This raises the very interesting question, will plecos eat apples?
Yes, plecos will eat apples. I do not recommend feeding your plecos apples as it can cause an algae bloom in your tank and greatly increase the bacterial growth.
How to Feed Your Plecos Apples
If you want to feed your plecos apples, which I don’t recommend, then you do have to take some steps to prepare the fruit for the fish. Preparation is not particularly difficult.
First, you should slice the apples. You should not just put a whole apple into your fish tank – the fish aren’t going to eat it if you do that. It’ll just float on the fish tank until it rots.
Next, you must figure out a way to make the apple slices sink to the bottom of the tank. Apples and apple slices float in the water, so you can’t just drop them in the tank.
I recommend tying a fishing line to the apple slice and then tying it to a rock. It will work to some extent, but eventually the plecos will eat enough of the apple that it will break free from the line.
A better alternative is to place the apple under some structure in your tank. This obviously only works if you have some structure in your tank, though.
Finally, you should not leave the apple slice in the tank for too long. 2 or 3 hours is the maximum recommended time. This should not be a problem as the fish will likely devour the apples slices – plecos really like apples in my experience.
Feed Plecos Apples Before a Water Change
Remember how I said that apples make terrible fish food because they can cause an algae or bacterial bloom?
This is why I recommend only feeding your plecos apple slices immediately before a water change. This way you will change out all the water and prevent any bacterial problems.
This means you can probably only feed them apple slices once per week at the most, which is fine. You will run into some algae problems if you put fruit in your fish tank every day of the week.
To summarize, plecos can and will eat apples. You should slice the apples before putting them in your fish tank and take them out after a few hours if the fish have not eaten them.
Figuring out a good way to keep the slices on the bottom of your fish tank is also recommended as plecos are bottom feeders.
Finally, you can eliminate some of the worst side effects of feeding your fish fruit (algae, bacterial growth) by feeding them apples immediately before a water change.