I've done some research on this topic recently and opinions seem to vary. I'm currently increasing my GH/KH from 4/5 to 11/9 in an attempt to successfully keep mystery snails again. I think a dGH of 10 should be fine for any snails; I added one degree just to be safe. Neocaridina (RCS) can handle a wide range of hardness, but you might be careful when boosting the hardness, depending on where you start. I recently boosted the hardness in my snail tank up to 14 suddenly (a miscalculation on my part) and this had the undesired effect of killing off a number of my adult blue velvet culls (also Neocaridina). The younger shrimp have thus far been unaffected, so I'm writing it off as stress due to the sudden GH spike. The snails didn't mind at all. In a few months I should have more direct information on how the increased GH is affecting snail shells (both mystery and red ramshorns).
I'm currently keeping RCS in a another tank with GH/KH 11/9 and I haven't noticed any attrition since boosting the parameters in that tank so far. I did this a bit more gradually for the RCS tank, so I would recommend that approach. Granted, I only did this within the last couple of weeks, but indications are good.
I've tried cuttlebone and crushed coral in the past with no real improvement for mystery snails. My water is pretty soft; I don't think they leeched enough calcium to really make a difference. I would recommend a product like Seachem Equilibrium that's specifically designed to boost GH; this is what I'm using now. An accurate digital scale and a calculator help for dosing here, particularly when doing water changes so the GH doesn't fluctuate too much.
Feeding a calcium supplemented food will be better--the idea is not to change the water, but to provide them calcium via their diet. They'll craze on the cuttlebone (or other shells in the tank). Google snail jello for a recipe, there are many options. It's easy to make.
Feeding a calcium supplemented food will be better--the idea is not to change the water, but to provide them calcium via their diet. They'll craze on the cuttlebone (or other shells in the tank). Google snail jello for a recipe, there are many options. It's easy to make.
Yes, everyone says this, but in my experience, diet (Ken's veggie sticks and home-made snail-o with calcium carbonate powder in it) and cuttlebone and crushed coral just weren't enough to make up for my soft water. I have graveyards of snail shells to prove this fact (ramshorn and mystery); the only difference I could find between my water and water used by other aquarists locally to successfully keep snails was the GH.
That said, I agree. It's best to start off with a high-calcium diet and supplemental calcium sources (cuttlebone, crushed coral, etc.). If that doesn't work, altering the GH of the water really isn't difficult to do with various aquarium products as long as you read the directions, pay attention to what you're doing, and do a little math.
I never had a problem with my snails shells rotting away until recently. I have no idea what changed. Population is in control and checked water prams (pH, ammonia, nitrite, nitrate) and they are good. So, I finally decided to get a hardness test kit, but quickly realized it was pointless unless I know what level it should be at.
That's 3 dGH - even lower than mine (4) and arguably too low for healthy snail shells in the long term. GH is calcium (absolutely critical for snail shells), magnesium, and other ions; KH is the buffering capacity of the water - this keeps the PH stable and above 7 which is important for snail shells as well - acidic water (PH below 7) will erode their shells. You have 5 dKH, like I do, which is okay, but could be higher.
I would try the suggestions mentioned earlier to boost your GH - the easy stuff first and then something like seachem equilibrium to boost your GH if those don't work. You can boost your KH using baking soda - do a search for aquarium dosing instructions for this. A digital 1/10 gram scale is the best way to measure dosing if you choose that path.
I'm targeting 12 dGH and 9 dKH in my snail tank and thus far everything is going very well, but I've only been doing this for a few weeks now so I don't have any long term data yet.
My RCS are doing well with 11 dGH and 9dKH so far - I haven't noticed any attrits yet. They can tolerate higher, but I would caution you to increase GH and KH gradually or you may stress them. My blue velvets in one tank didn't react well to increasing GH too quickly.
I use Seachem Equilibrium to increase my GH and Seachem Alkaline Buffer to increase my KH. I can't vouch for clay products as I've never used them before.
In a few months I should have more direct information on how the increased GH is affecting snail shells (both mystery and red ramshorns).