I have Apple Snails, Ramshorn Snails and Malaysian Trumpet Snails in a cold water tank, can you please let me know if your calcium liquid is ok for them.
Snail farmers have used Nutrobal on-feed but for aquatic snails which eat by rasping from plants this isn't an option. Making sure that the water is hard would be the simplest way of maximising their calcium levels. they do need exposure to light for vitamin D3 production from UV.