Thanks George, i understand now. I think i will have to make another.
"George" wrote in message
news:gvUje.26827$796.6441@attbi_s21...

"Paul" wrote in message
...
Thanks, but what do mean by add a "CELL". I have approx 20 goldfish in
size from 3" to 6" and three KOI sizes from 3" to 8".

Those goldfish will reproduce fairly rapidly and the koi will get very
large in a few years. In the next two years you will likely need a larger
filter than what you currently have made. What I mean by a cell is that
you have a rubbermaid box that you have converted to a biofilter. That is
what I call a cell. You can add another "cell" which will increase the
capacity of the filter by making another one and connecting it to the
existing one or build a larger one. But eventually, your load will become
to high and you'll have to "cull the herd".

"George" wrote in message
news:XrRje.25397$WG.8217@attbi_s22...

"Paul" wrote in message
...
Hi, was wondering if someone could tell me if I did the right thing
here. I built a Biofilter for my pond.It is 12X7X2. The one I built is
9gal. basically a square Rubbermaid box. The pump (1200gph) pumps into
the "top" of box through an 18W UV light, then goes into filter through
a 1 1/4" thick Med. filter pad. It works its way down through the
filter media. The media is a combination of Bio Ceramic Barrels,Two
bags of Lava Rocks crushed into smaller sizes and regular Supra media,
then finally exits out the bottom into pond. Will this design keep
water ok? Thanks..............

The efficiency of any biofilter depends mostly on the bioload in the
pond. I suspect that if your bioload is low to moderate, it should work
well for you. If it is high, you may want to attach an additional cell
to the existing one. Having said that, I wouldn't go through the trouble
until you've let this one run long enough to see if it is going to
handle the load. If it does, then you're done. If not, think about
adding another cell. The wonderful thing about biofilters if they are
constructed properly is that you can always add more cells to the flow
(if you have the room).