Hey everyone, I'm a newbie at fish and have a couple questions. I know my questions might sound silly to the experienced ones, but I'm trying to understand keeping fish as I've never had them before. I have a 20L that is set up and I just added bio-spira tonight. After it was added my readings are as follows: PH = 6.8 Nitrates = 20 Nitrites = 0 H = 25 Alk = 40 Ammonia = a little less than 3.0 Temp = 80 I have about 2 inches of gravel, a few fake plants, a filter, and airpump with stone, some hiding spots, a temp guage,... Do I test the water daily until the nitrites and the ammonia are 0? What level should the nitrates be? Do I need to do a partial water change before adding fish? I plan on adding a couple each zebra danios, tetras, dwarf gouramis, a mystery snail, an otto catfish, and maybe a red fin shark (the smallest kind). And maybe a couple other 1.5 to 2" fish. Would I add about half the fish at first, wait a couple weeks and add the rest?