does any one here have any suggestions on this topic,i have a fluval 404 on a 55 gallon tank,i am running the filter as follows,sponge carbon nitra-zorb,then finally the spagetti stuff known as the biop max,it was up for two days waited for the temp to stablize then i added gold fish five and 3 platy's,yes they are alive as we speak,i then let it cycle like that for tweo weeks then added 9 other small fish a couple of barbs neons,i then left tank as is for 4 weeks testing every week,no water changes as the water has always tested good to perfect,just a little cloudy,i gave the gold fish to a friend and added a few more small fish,still a little cloudy,so as suggested everywhere i have looked i changed 20% of the water making sure that the water was close to yemp as i used only bottled water 10 gallons,it has been 8 days and the water is disgusting it has never looked so bad but it still tests perfect,please someone get back to me as this is very fustrating and i dont want to harm my fish