I am new to this hobby. I have a 46 gallon bow front tank with 65 lbs of LR, 20 lbs of LS, 40 lbs of Crushed Coral, 3 pajama cardinals, 1 damsel and 1 half-black angel. My tank has been up and running for about 8 weeks now. My ph is 8.2, ammonia is 0, nitrites are 0 but my nitrates are 40...