hey guys, new to the forum, gonna give a detailed run down of the aquarium in question and my background, sorry if its a bit lengthy. Im just a bit stumped! I'm 37 and have been keeping fish since I was 11. Seriously keeping since I was 20. For many many years i had 15 10 gallons dedicated to breeding various snails, shrimps and other inverts. Was very successful. Had a 30 nano reef, and 280 reef, and 10 100g fresh water a 55 fresh and so on. Kept many various fish, mostly wild or F1 cichlids. Bred them and sold. I did this for about 15 years and had a lot of fun doing it. I had a few kids, starting my family and sold it almost all off. I kept an 80g tall and a 30 tall. Im very aware of all the ins and outs of keeping fish, and doing so responsibly and with healthy aquariums, but I've never ran across this problem. My 30 gallon is a deep sand bed planted tank, glass top with 3 dome plant lights (appropriate to the plants in the tank) it has a cluster of drift wood and a few aquarium safe rocks. Its a low tech planted tank. Its been running for about 7 years with no problem. I do appropriate water changes and the lights run about 7 hours a day. It is very over filtered with an aquaclear 70 and an aquaclear 50. Neither filter disrupts the sand tho. Temp is 78f. It has ran this way with out change for ever. It has 2 marbled crays, a bunch of mts snails, 2 bristle nose plecos and about 8 guppies (and come and go babies obviously) here is the problem. Over the last couple months the filters get so dirty its unreal. With in days they both have thick clogged sponges and same with the other media. I mean thick sludge that causes the inserts to rise and lift the top of the filter lids. When I clean them its as if I havent for a year. And man they stink like I havent for a year. Its gross. Water has under 5 nitrates, and is Crystal clear. I dont have an algae problem. Plants are great as always. Fish are healthy. I dont over feed. I probably slightly under feed. I use prime water conditioner with my regular water changes. The filter inserts are cleaned and replaced as they should be. Literally have never had this problem with any tank ever, and nothing has changed with this tank. So I'm baffled. Why do my filters (inserts) look, clog, stink, and act like the are from a neglected aquarium that has not had a water change or filter cleaning or filter insert replacement in several months when i clean the inserts, replace them when needed, and do regular water changes and have excellent water quality / consistent water changes in an aquarium that hasn't changed anything in ages? Thanks for your insight!