snails dying

I've lost several snails lately, all parameters correct, use ro water to top off and for water changes. I just don't understand what the hell is going on, could somebody give me an answer? The the tank is 6 months old I have algae I just don't understand I'm very frustrated at this point. Later....

 

What type of snails are they?

Do they have enough film algae and other algaes to eat ?

Check for a small snail that resembles a grain of salt as some types are preditory to snails.

Have you checked at night with a flash light for preditors?

What is the SG and pH ?

 

Additions to corailline's questions:

How long have the snails been in the tank?

What else is in the tank? Fish, inverts, hermits, etc.

What are your params? (I don't know if you really know what correct is or not)

Have you tested for copper?

You say you use RO water for WC. I use saltwater when I do a water change... Does your SG swing?

 

Agreed with above. Is there enough food for them? copper? and ph swings all things that effect them. I have had some snails that have made it years and other species I notice I lose some after 6-12 months.

 

Water changes w/ro and salt, sal 1.026, ph 8.2, ammonia 0, nitrates <5, nitrates 0, temp 80, alk 7 1/2, thats a little low, ca 400 have lost dwarf ceriths, and also nassurius, about 5 all together. All water changes are identical to aquarium parameters I don't have a copper test, using ro would there even be a risk of copper being in there? All snails have been in there almost 3 1/2 months.

 

The alk is something i would watch I perosnally dont run sp gravity that high and I keep temp at 76-77. nothing is deadly off but not how some may keep it. Inverts like 9-11 alk. I am not a pro at this even with a multiple year old tank I still ask chem questions.

 

I'm getting ready to change my salt mix the alk, mg, ca are always low, but these snails have been in there 3 1/2 months just all of a sudden they don't like the parameters seems weird.

 

It has been my experience that when you get a CUC sometimes you get too many snails and the weak ones die out because they have to compete for food. Usually it is a slow process over a couple of months.

Usually swings in pH and SG kill them pretty quickly.

I have had polyclad worms, hermits, starfish, pyramid snails kill them as well.