I dont do the calcium reactor thing but can you explain the fish goop idea to me??
Ok, so you know how you can buy clams that are frozen on the half shell? Or mussells or really any bivalve?
Some of us make our own fish food. It's a stinky (supposedly) delicious mess. Typically, it involves blending a large amount of various fish foods (shrimp, bivalves, squid, mysis, nori, etc.) together, and then mixing a binder (like gelatin!) into that. Instead of just freezing/chilling it into blocks, I bet you could put some on the half shells, and use that as an enrichment supplement.
I guess the most applicable fish that this would work for, would be the puffers and tobies. We know that they absolutely adore clams on the half shell. So if one had a bunch of half shells (like you), they could just put the fish goop onto the them. This could probably also work well for other benthic feeders like angelfish.
And for larger puffers, you could go all patissier. Toss the food onto the frozen half shells, and then once that has frozen, dab a little bit more on, and smush them together like a macaron...a very fishy smelling macaron that only large puffers and other bivalve eating fish would enjoy.