[tinman]

If it were me I would pull the sump if possible and do a water change and also get some carbon going in a high flow canister filter.......go to home hardware they have the silicone you need says right on the tube aquarium safe and cheap like 3 big tubes for 10 bucks. Then redo the sump and razor blade it super clean,rebuild it and let it set up for 24 hours then you should be good to go.