All you need is to reduce filter capacity, turn off UV light, and feed more. In
a few days, you'll get algae. My aquarium is full of algae on the glass, yet
have clear water.

JEFF UK wrote:

Hi.
I have a grey moulded fibre glass pond.
I hate the colour.
How can i encourage moss to grow on the grey fibre to make it look natural ?
Paint it with yoghurt ?
Any ideas please ?
Regards Jeff