Nitrates and clams..

[jamal-188]

What levels are nitrates dangerous to clams?

I'm having problem getting my nitrated down. They are at 40 in my BB tank and I've been doing weeking 35% water changes.

Will 40ppm or less be toxic to a 3" maxima? My LFS has some super nice ones and I"m afraid to pass them up...but I would'nt want to endanger the life of a new clam

 

[Don_Gnomio]

i say wait till nitrate is at 0ppm or as close as possible
ask the store if they can hold it if you put a deposit on the clam or something (hey, its worth a shot )

but eigther way i would wait.

 

[parothead22]

Tridacna's require nitrate for food! I wouldn't go any higher than say 10-20ppm though. The reason for this is that nitrate is associated with nitric acid which causes pH to fall thus inverts and corals cannot deposit calcium carbonate, because both the carbonate buffer is depleted and ph isn't ideal for calcification.
At the 10-20ppm range you will notice a more rapid growth in corals and nitrate again is food for the zooxanthellae (oxygen/co2 transfer).
One last thing to mention is that with elevated nitrate levels and increased growth in soft and stony corals, your calcium levels will become depleted if no dosing is done. Also, your alkalinity level will decline so make sure to test frequently to maintain alkalinity level around 7dKH!

 

[jmaneyapanda]

Parrothead, I am not trying to be difficult, but to clarify some points you made, and give my opinion.
This is a strange ball of wax. clams do not suck up nutirent as much as people think. Yes, they do need a nitrogenous food source, but suggesting elevated nitrate is a hornets nest. Most of the time, there is suitable nitrogen in the water from fish and coral waste, feeding, additives, etc. puirposefully keeping nitrates high is quite a game of roulette due to the consequences if high nitrates.

nitrate=nitric acid, so you are right, they are (very very) closely related.

 

[critterkeeper]

Without any real experiments - this is all nothing more than guesswork. Back in the "old days" (early 90's) when I was running bare bottom tanks, my nitrates were always over 20, and it never seemed to bother anything. I do wonder how jamal is doing 35% weekly changes and still keeping it at 40 though. Jamal are you using tap water? If not, you must be way overfeeding you tank.

As far as having too much for tridacnids goes, some clam farms literally pour fertilizer in their raceways to provide it... I don't know what ppm they reach, but it seems that it would be higher than what we get in tanks. Still - that's only a guess, too.

Lot's of guesses on these boards...

My two cents - better safe than sorry (always) - figure out how to get your nitrates down to at least 20. I can assure you from years of experience and keeping numerous clams in bare bottom tanks that it's safe.

 

[jmaneyapanda]

I can share my experience, not exactly a controlled scientific experiment, but pertinent nonetheless. I once had a 20 gallon seahorse tank that had ridiculous nirtrate at about 40 also. so I put 3 maximas in it for 2 months. Did 2 gallon weekly water changes. fed small amounts (I only had 3 seahorses in there). The tank had live rock and a few mushrooms and zoanthids. No skimmer on the tank. The clams grew, and did fine. I didnt see much reduction in algae growth, but I thought for sure the nitrates wouldve been down. I measured again- 40. ***??!! The clams did little or nothing to solve the nitrate issue. Since then, I have NEVER run a tank without a skimmer, but I was realsitically informed as to the "filtration" ability of these clams. Perhaps some less, or non-photosynthetic bivalves will filter more nutrient from the water, but I have experienced that the tridacnids (or more correctly, at least the maximas), do little or nothing. Just my experience.