Benjamin Woods wrote:
I wonder if anyone has used a Trident Topflow Biological Filter. The
filters are made in the UK, and are made of the box type design
consisting of three layers of foam mat and some Flocor medium below.

I thought of buying one until I saw the price of them.

I purchased and installed two 12000 litre filters to filter my 2000
gallon koi pool, within days the pool became and still remains like a
sewage works sludge tank.

So what did you have in the pond before?

If this is just a bio filter, what do you have as the mechanical filter?

One of the problems is that the matting fits
the tank until the tank is filled with water whereupon the tank
distorts in shape and leaves a one inch gap between the filter wall
and matting. Water therefore bypasses the matting.

I suppose it depends on the flow rate but I would have thought that some
would go through the mats and some by-passing them. Of course if your
mats are clogging up then you've got a problem.

I have emailed the Company to complain and was met with a tyrade of
arrogant abuse. The Company states they can produce a lot of letters
from satisfied customers, and yet when I ask them to do so they have
refused to make these available.

Oh dear, if you're in the UK, you could always try Trading Standards.

Please, please please anyone thinking of buying this type of filter
please think again, learn from my expensive experience, get a proper
Koi Filter system and do not waste your money of these filters which
basically are sold and constructed by confidence tricksters.

Go on, make your own filters, you know it makes sense.

--
Matt Helliwell
Matt at Matt The Rat dot com