As melosu58 said, lighting is the immediate issue, that and water changes; a alkalinity of 2.8 isn't going to cut it. What brand of salt are you using? Your alkalinity should be reading around 11 or higher (if you're measuring dKH
) or 200ppm (if you're measuring calcium carbonate alkalinity: CaCO3). If possible, rather than using tap water, get RO
water from your local supermarket or grocery store (usually in bulk water machines, not in jugs). Second, do not put anything else living into your aquarium at this point; you have not completed cycling until your ammonia and nitrite are reading zero. At that point, you need to do a major (20% or better) water change to drop nitrates. Then you are done cycling, but your tank is still not going to be stabilized, probabaly not for another 6 months to one year. Once the cycle is done, you will get a diatom bloom, then a hair algae bloom (most likely). I personally prefer to wait till after the blooms to add corals, otherwise they are going to get covered in the algaes and most likely die due to lack of light.