 | Crystal Blue Crystal Plex Algae Control. Apply one gallon per surface acre of water Split application works best 1/2 pond at a time Can keep working for weeks from one application Water needs to be 60 degrees or greater There's nothing so nice as a pond that's clear, clean, and free of gross algae. One of the best ways to keep it that way is by using Crystal Blue Crystal Plex Algae Control. The temperature needs to be above 60 degrees to work, so do this when it's warm out. You can split up the application if you need to—it works best... - Crystal Blue Crystal Plex Algae Control. |