[jjgina]

I just started a 35 gal w/ 20 lbs. of live rock and 40 lbs. of live sand.
The tank is cycling and had no fish in it yet there was ammonia present. Does the organisms in the sand and rock give off enough ammonia for this to be what I am reading? How come I barely read any nitrite, shouldn't that be increasing with the ammonia? Nitrates are at 10ppm right now, how high will they get when the tank is done cycling?

[naser]

it is probably just things dieing in your live rock.

[Aragorn]

JJ,

Ammonia is produced by organic matter decay. For example, when one places Live Rock in a tank there is bound to be some "die-back" of the organisms living on the rock. The decay results in the prescence of ammonia. However, there also exists on(and in) the Live Rock...and Live Sand bacteria. These are known as nitosomas and nitrobacters. Ammonia is a "food stuff" for nitrosomas. They will consume the ammonia and, as a waste product, produce nitrites(still toxic). The nitrobactors however use the nitrites as their "food stuff" and produce nitrates as a waste product. This is why one gets the ammonia spike first, then the nitrite spike, ending with the nitrate spike. Nitrates are non-toxic to fish, but in sufficient amounts is toxic to corals. This is why water changes are so important(removes nitrates). Additionally, with the incorporation of macro algae for filtration, the macro algae will "consume" the nitrates and safely lock them away. HTH