I have an approx 6000L outdoor pond with 10 goldfish and a few plants. Black plastic liner.

I currently have a mechanical filter - essentially a big black box that water is pumped in and then through 3 layers of varying coarseness sponges. Water is then fed back to the pond.

At this time of year the pond water is pretty green and the filter is getting full of brown sludge and little (1cm) red worms and is requiring cleaning every couple of weeks. Basically it's not doing the job!

So is it worth trading up to a mechanical / UV combined filter - such as:

http://www.trademe.co.nz/Home-living/Pe ... 181789.htm

Great Pond Bio Press UV Filter 10000L/H

Anyone got any experience with this sort of filter? Do they work? Etc etc.

Or what about an 'inline' UV filter to add to my current system such as:

http://www.trademe.co.nz/Home-living/Pe ... 466439.htm

(hope the links work)

11582 PONDMASTER UV-C 9W CLARIFIER

Thanks

i had a problem with my large pond going green and used a large uv unit on it but still had problems

i ended up using TLC freshwater S.A.T a product used by our local council to treat large settlement ponds in the area, it solved my problem

this should be available through your local fish shop

this is their webpage with different pond treatments

http://www.tlc-products.com/pages/7/index.htm

Thanks for that Livingart! I shall seek it out and give it a try. Any idea of costs?

Don't throw out the worms as they are probably bloodworms, tubifex or Lumbriculus (blackworms), all of which are good fish tucka

I have a similar type of filter on my pond. A certain amount of sludge is good, unless it is impeding the water flow significantly.

My pond has gone very green at the moment (it was crystal clear all winter) but our pump died back in May and I am still waiting for Grant to finish hooking up the new one :roll: