I noticed one of my assassin snails has some holes forming on its shell and read that cuttlebone might be able to help. Question is, will it affect my pH? I also have some angels in the tank and would rather keep the pH as is.
Probably depends how much you use? I'm not totally 100% as I've never done it myself with cuttle bone. Assassin's though, they only eat snails? Will they go after to eat the cuttle bone? And I'm not sure if adding liquid calcium to the water would change the pH either.
Cuttlebone will affect the pH and cause it to rise slightly. Liquid calcium does nothing for the inverts. Snails need to intake calcium from within their food, much like our need for Vitamin D. Some snails have a pouch within their mouth which is where the calcium is stored.