Unfortunately, most filters are sized to the number of gallons of pond,
which has absolutely nothing to do with the needed size of the filter. They
also advertise a size that is at least double the capabilities of the
filter, based on normal fish load. The bubblebead filters are rated on the
basis of pounds of food fed, which is getting closer to the right formula.
For outside ponds, there is a certain amount of plant material, leaves,
pinetags, etc. that also have to be processed, but for an aquarium, that
might be able to be ignored. The number of fish, and size of the fish,
determine how much food is fed per day, and between the food and the natural
fish waste, you need a filter large enough to handle all of that.

The Sequence pumps are very good external pumps that will move the quantity
of water you are looking to move and they are fairly quiet, but do produce a
constant sound that can be heard if you are in the same room.

The canister type bead filters, (aquadyne, advantage), can be located
anywhere, and would work best located at ground level, so that the cleanout
could be done without 10 foot of back pressure. The better ones use a
jacuzi air pump to clean the beads and assist in the backwash, limiting the
amount of water required for cleaning. Backwashing will use about 50
gallons of water or so, and that is good for the recommended water changes.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html

"John " wrote in message
...
I know this is a little out of order for this group, but I know that many
of you deal with large to medium size ponds all the time. And winter tanks
of this size every year.

I just purchased a used 850 gallon aquarium,
http://www.noahs-marine.com/aquarium/ and need to figure out what to do
for a filter. This tank will have several FW game fish, Bluegills,
Crappie, Perch, Bass, Catfish & Northern Pike. Besides all the politics
and comments about FW fish in captivity, ALL of these fish were born in
captivity and have never experienced real water.

Anyone have suggestions on an appropriate size and type of filter for this
system? I would prefer a closed loop type of system, canister or pool
sand filter, however I have been toying with a wet/dry sump or trickle
filter. It seems the consensus of rec.aquaria.freshwater.misc lean towards
the pool filter, but how much capacity do I need for this tank?

I know I will have a pretty heavy bio load with these fish.

GPH? Filter size?

I see 17" to 31" - 3/4HP to 1.5HP - Flow rates in the 25,000 to 50,000 GP
24 hour

What about noise levels? This filter will have to be inside, is the noise
tolerable?

Question about backwash? Is there enough pressure to pump the backwash up
10' and go 30 feet away?

Thanks I really appreciate any and all comments about this project.
John Lange