Summer Algae.
Remedy water soluble food dyes (E133), non toxic to fish, however underwater plants will be effected as they cut out UV light.
Caution please makesure that you use "food dyes" as other dyes could cause damage to the pod life - all food dyes have preceed with E, I have suggested E133 which is a blue colour.
This dye will hold its colour for approximately 1 month before fading.
Reputable sellars will be able to provide a "Material Safety Data Sheet - MSDS".
Quote:
Originally Posted by Geoff Lane
I've just installed a small prefabricated pond in my garden, no fish but
a few plants. Intention is just to attract wildlife and I saw a frog
dive in yesterday evening 
Trouble is I am getting a greenish film on the surface, a net doesn't
pick up anything.
The pond gets full sun until early afternoon and hen light shade, it is
not directly overhung by trees.
Anyone any ideas as to the film and a possible remedy.
Geoff Lane |