All my levels are correct, nitrate 2/3 is at 0, ammonia 0, ph 7.4, salt is at 1.020, and temp 80.9. Water is cloudy, water change last weekend... What could be causing the redish flare-up? Tank has been running for 4 yrs. now. Size 50 gal. with Tang, and two Tomatoe Clowns. Please advise...is this a concern ?