I don't have experience with any of the ones you mentioned, but I have an
Ultima II hooked up in my system. I believe that all bead filters have
similar requirements that cannot be ignored, so be advised in advance: in
order to work at their optimum, your KH must be 200 or more. That's easily
done with baking soda, which also works to ensure a completely, rock-solid
pH. Also, you should have a 2 speed pump: you run your filter normally at
the low speed, but when you backflush, you need the WHAM! of the high speed
to knock everything out. I only have a one-speed pump; if there was any way
I could justify the purchase of a 2 speed at this point in time, I would. In
order to clean my filter properly, I have to go "backflush/rinse" at least 3
or 4 times. Every time the water looks like its finally running clear in
backflush, I find that it's a far cry from clear on the second (or third)
round. The 2-speed pump would take care of that. On the flip side though, by
the time I finally get it clean, it's the same amount of water I'd have to
remove for my 10-15% weekly water change, anyway!

Good luck with your choice.
Lee


"Tony & Diane VonNeida" wrote in message
. ..
I'm seriously contemplating purchasing a bead filter for my 8500 gal pond.
I'm looking at Aquadyne, Challenger 60 by Fluidart, and also Aquabead.
Wondering if anyone has experience with any of these? Would appreciate
all
opinions.
thanks,
tony