hi all so i would like some advice really i have a fluval 205 and 305 in my 200liter tank (whats is the lph they do together) and i carnt get rid of the smallests particals in my water, this is what i have in my filter i have carbon on the bottom and then filter wool on the 2nd and then bioballs on the top also i have the filter sponge in the fitler sponge holder what else could i add to keep the water crystal clear i do water changes every 4 days of 50% and also a gravel vac i currently have 1 oscar and 1 parrot cichlid