The water in my tank always seems to be a kind of brown/cloudy colour, never seems to clear up. Stocking is in my sig, running an APS 2000 lph external filter and a Fluval 2 internal filter. Tank has 4 decent sized pieces of bogwood but even removing these for a while didn't clear the water up properly. I'm doing 50% water changes per week. Any ideas on how to clear the water? Driving me crazy!