Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Green Film on pond

I now have a green film on my pond after the Tilipa took care of the filamentous algae problem.. Is this normal? I have noticed, after a rain, its not there anymore.. but after a few hours, its there again

Again, after todays rain the film is gone again..I'm Very confused

Is it a film or a gritty coating? Sounds like watermeal.

No its a thin film

This is very probably another form of algae bloom. Nutrients were not eliminated from the pond. Tilapia just ate the filamentous alge and converted the filamentous nutrient laden algae into manure. High amounts of dissolved or suspended organics can stimulate Euglena (algae) blooms which often form green films on water surface. Sometimes these films are describes as looking like green paint. Also other types or species of algae can form green films on the surface. Terrestrial plant pollen (often from trees) can also form green films on the water. Microscopic examination of the water is necessary for a specific determination.

Bill:

In small to moderate amounts, is Euglena good, bad, or indifferent to fish health/growth?

I had a similar experience. The film had no odor or feel. I believe it happened when I was changing from one food to another. I thought the tilapia could use a larger pellet, I was wrong, so switched back. But, within a few days I noticed the film, about two days later a slight breeze pushed it all into one corner and the small tilapia appeared to eat it. Later the fish were large enough for the larger pellet food and again I noticed the film. This time, after 4 or 5 days, it appeared to develop into small clumps of green algae, 2" or 3" across. I skipped feeding for a day and the tilapia ate the algae, very impressive to see them doing their job. Coincidently, I finished the food and switched to another around the same time and have had no film since. Additionally, the food left an oily coating on my hand.

Rad,

You make a very good point...those who are stocking Tilapia for algae control should seriously consider not feeding them until the algae is under control. They are ravenous eaters of algae when not much else is available; less so when artificial feed is available. They still eat the algae, just not so ravenously.

Update.. The green Film has been gone for almost 36 hours.. Thanks for you folks help