Hi I'm doing my first reef tank on a 20 gallon tank I'm doing the cycle on tank its been two weeks I do a 5 gallon water change ever Friday I have Crush Carl rock as a bed. The Ammonia 0 no2 is at 1 and no3 at 80 salt level is 1.023 According to my test kit.. So my tank is starting to get Brown on the bed which I believe is part of the cycle I just wanted to make sure its normal or something going on with the tank And I do started with Purple dry and live rock.