Hi guys. I'm experiencing slightly cloudy water after a water change and filter media clean in old tank water. I'm using the fluval u4 internal filter. I think I'm slightly over stocking my fish tank. 1 tiny golden severum, 2 angels and 5 silver dollars. Thinking of upgrading my filter. Anyone had or have experience with the Aquael Internal UV Filter 1000? Used on tanks 250L to 350L. Thanks!