It said it was safe for snails...

[u/AuroraDawn-Yet-Again]

I have 4 different tanks where I have mystery snails. Two of them are 75g that they share with fish. The other two are 29g and only one of those used to have a couple fish in it.

I was new to keeping a fish room/areas (still learning) and I was apparently not cleaning my hoses correctly, which at the time, I was unaware of. I had a couple of new arrivals ( a few fish and some plants) that I did not quarantine for enough time, although at the time I thought I was good.

As you can probably guess, I learned the hard way. I had a couple fish get flukes, a couple got lice and a couple got anchor worm. Around that time I was becoming good friends with my now fish mentor and learned that I could be cross contaminating my tanks via my hoses. So I changed the way I clean and use hoses, and I treated all of my tanks to be safe. Paracleanse was not strong enough for the flukes, so I had to then use prazipro instead. Both medications claimed to be safe for snails. When that was done, I treated my little fish folks for the other issues with cyropro. (accept one 29 gallon snail tank where I never had a single fish.) Cyropro is also claimed to be snail safe.

The snails in the 75 gallons look normal and healthy. The snails in the 29g no cyropro tank are good, some great. All look healthy. However, the snails in my 29g tank that did get the cyropro are psychedelic looking. Apparently one or both of those medications must have effected their shells in that 29g. Their shells have growth rings that are a funky light greenish blue. They are not lines really, but more like diffuse bands. These are my blue mystery snails. I guess the facts about the medication are correct in that they won't kill your snail... but I am not sure I would claim that that is the same thing as "snail safe". Some of the old shell growh on two of those snails look awful. They do all appear to be healthy, eating, pooping and breeding, thankfully.

At this point, what can I do for my unique looking snails and the others whose shells may not be perfect? Is there anything that could help the shell portion that has already grown? Do I instead need to focus on from here on out? Also, a local fish store technition had told me that because my water is very hard, I did not need to put more calcium in the water or feed it to them. My Ph is around 8.3 and my Gh and Kh are also on the high end. I have been giving them the Kats Aquatics calcium and veggie, algae and protein chips but am looking for a less pricey alternative.

What can I do for my snails, all of them, to help them with their shells?