boB,
I have very few snails in my three BB tanks. The 37g has about 5 astreas and they seem to be doing okay. In my 67g, I have maybe two astreas and three ceriths, and have thick algae on the back of the tank that needs to be cleared up. In my 120g, the tank of death for snails, has both astrea and margaritas. There are only a few left and in this tank I also have the back coated with algae. Since feeding the 120g four times daily, the snail death rate has diminished substantially, so I'm thinking the flame back angel was killing the snails. Now that this fish is getting fed more often, in small quantities, I believe my snail deaths will be very low from now on.
However, none of my tanks has near enough snails, so I can't properly determine if the algae build up is due to the wrong snails or the lack of them
Did a quick search on the two snails you mentioned. Stomatellas come out only at night and trochus can get to be 8" - a shocker
