1. Get a good test kit, and find out what's in there AND what's in your fill water.
2. If you have suspect fill water, do a WHITE bucket test on the fill water.
3. If practical (based on testing, and bucket test), chlorinate the heck out of it.
4. Get high quality Unicel cartridges to replace the low quality (have to clean and then toss) OEM cartridges.
5. See if the goo can be settled and then vac'd to waste using a manual vac and siphon.