clams/ nitrates

[TruonkQ]

I've had my huge tank running for about 3 - 4 months and can't get the nitrates to go down bellow 20. Its fOLR as of now, but by next week i plan to get some softies. Is it safe to do that? Everything else i tested is perfect except the nitrates around 20-30. I thought about that sulfur denitrifier, but couldn't i just add more clams? Anyone know how many clams i need to drop nitrates down to 0-5?

[loans_n_fishes]

I would think algae like chaeto would be preferable and may be more efficient and cheaper than filtering with clams. (Am I right, people?) Although, I would really like some of those filtering clams myself...they are cool. I may put some in my tanks sometime. Where did you get yours? Will my fish think of them as mussels though ie: eat them?

:unsure

[GaryP]

Both macro algae and clams will reduce nitrates, however macro is more efficient, simply because it grows faster. I feed my fish mussels every day and my clams have never been touched. This includes my CBB. As a matter of fact, the first night my CBB was in the tank it picked an aiptasia off the shell of a maxima with surgical precision. The aiptasia was growing very close to the mantle of the clam and I was very concerned that the clam would get stung.

That said, CBB supposedly can sense a stress hormone produced by newly introduced clams that is an unresistable feeding trigger for them. Instar recommends covering a newly introduced clam with an eggcrate "cage" for a week or so until it gets over the stress of being moved and acclimating to the new tank. I think this phenomenon is largely responsible for the undeserved reputation that CBB have as being clam eaters. Perhaps being underfed is another cause as well. The same applies to the reputation that some angels have as well for eating corals. Many are probably just underfed. There was a great article about this in Coral last year.