I've had to remove the plants from my largest aquaponics set up, as all have gone to seed. Anyway I stuck some weeds in to keep it going through the winter but I'm also getting greenwater now to.

If I keep the tub with the green water is there anything I have to do to stop it getting out of control? We're on tank water so large water changes aren't an option. Filtration is very light as the aquaponics requires a slow flow, so the tubs only turned over once per hour. So far the water only has a light greenish tinge and a lot of hair algae growing in the yabby tubs (yabby tubs are hooked into the same filter) which the yabbies have greatly enjoyed eating.

Thanks
Emma

It may or may not go away on its own. A UV light installed in line would be good to stop it though..

I suggest UV along with barley straw extract. Whatever you do, do not use any type of algae destroyers. I currently have a UV (cost 70$) that is keeping my pond crystal clear. Too clear actually :-). I also periodically use barley straw extract. That is also natural way to control algae.

There's some really good information about algae here: Robyn's Pond Algae Index.

So far, we've been successfully controlling our algae by having lots of floating plants and water lilies that shade the water, in addition to a large number of snails who eat algae... so far so good!

That's good information spiffy! How big is your pond and how much sun light does it get? 90% of my pond gets sunlight all day long. So I had a serious problem with algae. And since it was beginning of spring, lilies were still dormant. So I started using UV and barley extract. It worked miracles !

My pond is about 30 gallons (there's a photo of it here: Pond Photo thread)! I guess it gets sun for most of the day, but it is partially shaded by some bushes. Luckily (?), here in Münster, we have a lot of mostly to partly cloudy days, so that sun isn't all that strong.

When we have lengths of hot, dry weather, though, we do get more algae. We'll just have to see how it goes later in the summer!! I'll have to keep the barley extract in mind! (I wonder if I can get it in Germany? I'll have to check next time I'm at the store.)

Edited to Add: It's sort of funny looking at the photo of my pond! It was taken about 6 weeks ago, and now we have twice as many of the floating plants and twice the number of lily pad leaves!! One can hardly see the water surface anymore!