Yes the water entering a fluid bed filter has to go threw mechanical
filtration first to take out most of the solids.
But for a 500gallon pond its probebly a bit accesive you would be fine
with a bog standard filter from the water garden centre just go for one that
says it will do up to a 1000 or a 1500 gallon pond and you should have no
problems with a filter larger than you actually need it will require far
less cleaning and you would be able to stock to a higher level. In my first
pond (500g) I had for six years several koi 3 largest 18inch each and dozens
of goldfish and with the filter being far bigger than actually required we
never had any problems.

Jon
"Mark T." wrote in message
...
Hi all,
I've been reading a bit about a
"Fluid Bed Filter" with coral sand in it.
The sand is supposed to swirl around inside
the tube. Apparently you can make a
pressurized vessel type as well so that you
can still pump water to a waterfall.
Would one of these work alone or do you
have to use them in conjunction with another
filter type? And UV light filters? I'm new
to the fish pond arena, (500 gal), and it seems
to be turning into a lot more hassel than it
needs to be. I'm pretty sure I'm doing it not
quite right.
Any ideas or help here? Information, websites,
etc.

Thanks,
Mark


Thanks,
Mark