Are crushed oyster shells beneficial or harmful to other fish?

[bettaMagenta]

I recently got some crushed oyster shells for my baby puffers, as it was suggested to mix them with repashy to help control beak growth. I found a small package of finely crushed oyster shells and I'm curious if other fish could benefit from this, or if it's best to keep it puffer-only.

If it's not gonna harm them, I thought maybe I'd mix up half a package regular and half with the shells. Worst case, other fish would just eat around the oyster shells and they'd end up as part of the substrate, possibly adding some minerals to my RO water over time. Thoughts?

[coltin]

I'm curious, what kind of pufferfish are you keeping, bettaMagenta? I think it's a great idea to mix crushed oyster shells into their food, but I'm not sure it'll have the desired effect on their beak growth. From what I've learned, puffers need to chomp on harder foods like whole snails, shrimp, or mussels to really wear down their teeth.

The shells in the water might raise the pH slightly, depending on the amount, and could also increase the KH, but it'll be a gradual change. I'm not too worried about it, especially since you're using RO water - it might even add some beneficial minerals to the water.