Ziggy953
Aquarium Advice Addict
Tap water and Prime are fine for FW. Reach in there and whip that mess off the sails, disturbing the fish isn't an issue. BTW Diatoms can and will stain things especially white things in the tank. As long as you don't have something in the tank consuming the nutrients, (live plants) you are going to continue to see algae and diatoms pop up.