Any thoughts on calcium requirements?

[MotorCityAquatics]

I've wondered about the calcium requirements of soft-water fish like discus for a while. I know discus come from waters that are soft so there is little calcium in the water. I assume wild discus get the calcium they need from their diets: the exoskeletons of insects and inverts and bones of small fishes.

But captive discus are fed beefheart, bloodworms, white worms etc, the occasional prawn but without any shell. They have a big skeleton and some have been selectively bred with larger and larger fins which require even more calcium. I've noticed the shells on snails I keep in my soft water tanks are more fragile than they should be.

I used to add Repti-Vite (which is a vitamin supplement for lizards that contains a lot of calcium) to my beefheart mix but I found it raised the TDS in my breeder tanks. My fish seem to thrive on the beefheart, bloodworms, and live whiteworms I feed them but I still sometimes wonder if I'm not missing this vital componant.

Does anybody have any thoughts on this or understand much about the nutritional requirements for healthy skeletons and scales in discus?

[Eddie]

Andrew Soh recommends adding a calcium supplement to mixes. I use Calcium Citrate as he mentioned this being the best source for absorption.


Eddie