sorry to dissagree clinton, but i think you are talking absolute rubbish!!! do you honestly believe this is the only product launched that had research and design money spent on it? as for the spec who needs a system that large? maybe industrial keepers,just read the back of the koi mag and put the two agains t each other, you can tick 7 of the 9 statements against the compaq. the compaq is brilliant, never overfills, if it does it has an overfill drain!! 50 microns difference in the actual sieve, its a con!! again,,, as i said i aint disputting what a good filter the nexus is, but the price is way, way over the top,, most business people may have a 10 year recovery plan, i think nexus have a 6 month one, the difference in the sieve is not worth Â£314,, anyone that wants a sieve try the compaq its a brilliant piece of kit.