Koi Pond Help

[Nofishing!]

I have dug a large koi pond in my backyard. It's about 4000 gallons. I need help choosing a filter, the oase bio tec 12 or 18 seems good for the money. What other good filters are in the 4000 gallon range that perform well? Any good advice is appreciated. Thanks.

 

[MBOU]

If you are going for Koi, just sponge filters will barely cut it. Might be worth having a small sponge filter running alongside something more heavy duty.

Something like an Evolution Aqua EazyPod or better still, Nexus.

I think the EazyPod inc the air pump and uv etc goes for about £500 or thereabouts.

 

[Nofishing!]

I need something cheaper. DIY maybe? The nexus eazypod is only for 2000ish gallons. I have a 4000 gallon pond. I need some thing that's around the nexus eazypod/oase bio tec price range. I found some good reviews on the emporer aquatics biopro filters. But they need to be placed after a prefilter. There is also the Ultima II filters. So which would be better. The Ultima IIs are very pricey! I think I will forget the bio tecs in my pond. Any other ideas out there? What do YOU use? Thanks!