I've been reading and trying to comprehend the additional readings for a marine tank, but i need to know if i am covering all the bases. i know that i need 0 for ammonia, nitrite, & nitrate i know i should maintain salinity(=specific gravity???) but i don't know to what level. i know i should maintain pH, and i'm gathering that it should be 8.2 or 8.3, but this also depends on species i guess. i know i should maintain a calcium level but i don't know to what level. and i see readings for alkalinity. this puzzles me because isn't alkalinity what you would call the acidic side of the pH scale with the opposite being Basic ?? i saw a couple of other readings given, copper and something else i think. any way, some direction on this would help. i already looked at the advanced aquarist.com and WOW, very technical. guess i need a chart or something that tells me what i need to be worried about, what the readings are for normal, and how to correct them. and don't worry, when i assimilate all this info i gather on 3reef, i will make some posts that other newbies will laud. again thanks for the info.