Whats wrong with my nirate snails

Hello,

For about 3 weeks now I haven't seen my 2 nirate snails. For the first 3 months they were going around the aquarium all the time, but now they just hide underneath the driftwood. I found both of them and they are alive but they are just hiding. I never kept snails before so I'm new to this. What is wrong with them? Is it a calcium problem? I don't have the test for calcium. Is it that or something else?

Thanks

Calcium only affects the shells not the behaviour.

It could be that they are hungry if your tank doesn't have enough of the right kind of algae. And the opposite could be true - if your tank has a lot of the right type of algae they could have over eaten and are sleeping it off.
You could try putting a thin slice of courgette/zucchini in the tank and see if they'll eat that. Blanch it for 30 seconds in a bit of water in the microwave, then weight it down with something - the edge of a rock or piece of wood, or even skewer it on a small spoon handle.

My nerites like wood. They are usually to be found on a piece of wood and there is usually a lot of nerite poop under the wood. I think they must graze on the wood.
Nerites also fall on their backs and often can't turn over so we have to help them. It's worse in a tank where the fish nip at them when they come put of the shell to try and turn over.

Thanks

there is a lot of alge (especially the one growing on glass thats easy to remove, together with some green and brown alge).

Speaking of calcium affecting shells;



Is the shell growing or is it calcium deficency

It's hard to tell from the photo.

How hard is your water? Mine is around 5 dH and the shells do erode slowly over time. pH under 7.0 makes them erode quicker. This snail died shortly after I took the photo last year but I did buy it in 2011. You can see a gap across its middle.

My Nerites are normally under my bogwood, Ive had them a while & have noticed after a big graze they do sleep a while.
Another is normally found underneath the inside of the hood