Cant get nitrite to zero

Question
Hi, I set up a tank with live sand and the live rock was already cured in an aquarium at my LFS. I test everyday and since day one my ammonia=0, nitrate 10, PH in normal range however a little lower than suggested for my tank (I have two seahorses with a clean-up crew of snails, shrimp, hermit crabs and one goby) that's all I'm gonna have for now. My tanks size is 25 gal. My nitrite has always been .25 to .50 and I don't know what to do to get it to zero. I would also like the PH to stay a little higher than 7.8. Started aquarium on 1/21/09, Added the livestock late 1/23/09 as my LFS said my tank would be instantly cycled and I could go ahead with fish. What do I need to do?

Answer
your fish shop lied, marine tanks can take a while to cycle, i think you have been lucky in the fact that you have had no ammonia spike and still have inhabitants alive in there.

for your PH you may find a buffer helpfull, not sure where you are and what products are available to you. also helpfull is keeping the gas transfer through the water high (exchanging carbon dioxide with fresh oxygen) as you have sea horses this could prove difficult as they need low water flow. i recomend you try a small powerhead placed so it disturbs the surface of the water.

the only really proven way to reduce nitrates is water changes, keep them regular and use a good salt when mixing (this will also help your PH) i also find having a good protein skimmer helps too. there are other methods but they are very complicated, may be worth looking into.

adding sugar to your system
adding vodka to your system

these are not to be tried unless you have really done your reading up on them.