My poor little filter in my guppy tank...it sounds like its dying after I do water changes. It was a mini-might filter that came with a glolight tank rated for 10 gallons. Its actually quite powerful but the motor makes a whiring sound right after I plug it back in after a water change, I wiggle the cartridge around and it sounds normal again...just wondering if filters have a difficult time handling the seasalt you use in the brackish tank?
Salt can causes a crust on the impeller, in the hoses, well anywhere the water flows. Its not the salt that causes issues, but the crust (likely carbonate). rinse the cartridge and leave it in the tank while you get out the lime-a-way, the bottle brush, the trumpet cleaning brush and the scotch-brite green scrubber and go to town on the crust.
This is another reason I like 2 filters / tank. So I can take one off and soak it.