Hi All,

I have a large spring fed pond, roughly 900,000-1,000,000L. 30m2 0.5-1.5m deep. It has had no love in 30 years.

It's full of algae and duck weed that is getting treated and dredged.

I'm looking to install some air infusion to help keep it clear but I have no idea or can find the formula to calculate the required flow.

I'm currently looking at this pump (150) and 4 diffuser stones.

Is this adequate?

http://www.swelluk.com/evolution-aqua ... POu56qR-tMCFYK37QodL7AKzQ

http://www.swelluk.com/swell-ceramic-air-diffuser-200mm/

Thanks in advance.

Hi You say you are looking for a formula to calculate air flow to help keep your pond clear. I am trying to understand, how did you come to that conclusion?

And did you notice on the link you gave in respect of the 150 pump it says

Airtech 150
code: AIRPUMP150 Out of stock (Notify me)
£264.99
£395.00

Hi,

I came to this conclusion because of following.

-My very basic knowledge that all ponds benefit from aeration.
-I have copious amounts of Algae on the surface and black sludge on the bottom.
-Unless you calculate aeration by sticking you finger in the air there must be X amount of air(O2) required per X volume of water.

Thanks for your response.

I see I should have asked what you mean by "keep it clear"

To most (and me) that means the water should not be coloured in any way.
The best way to do this is to have a biomechanical filter and a UV.

Duckweed is a real pain, but the easiest way to get rid of it is to over fill the pond / pool and let the duckweed float away with the excess water.

Sludge being dead / decaying matter should really be removed by mechanical extraction. There are some "chemicals" that claim to remove it, but it has to be some where, so if you want rid of it, you are going to have to "shovel" it out (all be it using a backhoe digger if you have to.

Air will only add oxygen feeding the plants you don't want.