Large outdoor scrubber

[ReggieTheDog]

Guys, I ned your help and expertise... I have outside a 40000 litre reservoir and I am desparte to get it clean and healthy. Allwo me to explain. We have 34 Indian runner ducks and 20 golden tench that enjoy this reservoir. Its two meters deep and crica 5.5 x 3.5 meters. My request is about a scrubber. I want to construct a horozontal scrubber to help clean it. I already have a 8000 liter per hour pump and I'm looking to make a scrubber that is about 70cm wide by about 4 meters long. The real challenge is what medium to use to help algae grow successfuly. I was thinking of something like astroturf to allow water to flow over and wondered if anyone had experimented with different materials beyond the obvious plastic canvas. Looking forward to hearing from those with experience.

[SantaMonica]

Welcome.

Astro turf will work; will be a standard horizontal river design.

[ReggieTheDog]

The design is fairly simple. There will be no moving buckets or anything like that, just a flat surface on a slight incline. It'll be facing south and will be in sun all day so hopefully it will work fine and that slight incline will help catch that sun in the winter months. The only niggle is that I don't know wether this will be big enough to fullfil the requrement. I've seen many aquarium designs and calcs re food and stuff but very little on ouotdoor larger designs... Any further thoughs/advice would be warmly received

[SantaMonica]

The larger the incline, the better, in order to avoid the algae islands that will block flow.

Outdoor is different because you are not constrained by size or light. And even if growth detaches it won't really matter.

[ReggieTheDog]

I never thought of Algae Islands before! Good to know... I was thinking of an 8-10 degree incline but may opt for lightly more. I'll have a trough up top to even the flow of water across the entire width of the astro turf but still remain unsure as to whether the size of the scrubber is right. Better too big than not big enough, thats my thought.