Too much calcium can be bad. TBH I don't know exactly what their calcium ratio is. I've heard a few numbers, but don't know which species that was for and how accurate it was in the first place. Their shell is made mostly of calcium from my understanding and they feed heavily on calcium/mineral rich foods. Some even need a regular source like cuttlebone available at all times. It throws off the phosphorus among many other things. Even in people, overconsumption of milk can throw off iron/zinc/etc. I've read the body takes calcium before other minerals and doesn't know to regulate it. That's why they say to take zinc and other minerals separate from calcium. Vit D and K can help the delivery system though to make sure calcium goes to the right place.
This isn't a concern if they're eating a few isopods every once in a while, but could be a longterm issue if they eat a lot of them daily. I usually feed some isopods or a snail once, maybe twice a week for my growing Parsons. Don't know exactly how many it'd take to cause harm, just more of a precaution.
People have also said they absorb heavy metals and pollutants. So might be a good idea to breed out wild ones to get fresh new generations.
Anyone feel free to correct me if I'm wrong.
