Nitrates

[michika]

Hey,

Left for the weekend, came back, nitrates through the roof. Everything else is testing at 0, SG is 1.024-1.025, and pH is running at 8.4 durring the day and 8.2-8.3 at night.

Aside from doing frequent water changes (which we've been doing since we've gotten back) is there another quick way to reduice nitrates?

The only thing that has been added recently is three snails and a clam. The clam which was open and seemed to be thriving Thursday evening has stayed closed all evening, although some of its mantle is showing.

HELP?!