I'm having an issue with bacteria. Tank is several years old. Recently removed sand to go bare bottom and then suffered 2 months of milky water. Bought a UV sterilizer which cleared it in a week. Now, I'm getting a mucus and stringy bacteria mess. I assume I upset the balance when I removed my sand. I added well cycled sand again 2 weeks ago to restsblish a balance. Will waste away help with is slime bacteria? It clogs my filter sock in a day. Should UV be off in use? Any other suggestions to reestablishing balance? Thank you.