"humBill" wrote in message
. com...

"NetMax" wrote in message
...
"John " wrote in
The PF 1500 also uses a very small pump (9 watts) which I'm
surprised even achieves 750gph.

Max - I suggest this is the humblest way, but I think your fit of flu
delirium kept you from deducing that the 9 watts is probably the
strength of the UV light.
Bill


Ha! ..you might be underestimating my ability to screw something up, but
you're most probably bang-on regarding the UV lamp.
thanks Bill.

I just now read your post. Quite right about these pond pumps having
nebulous flow ratings. Some of the better ones at least show the drop in
flow as a function of head. We used to subtract 100gph for every inch
up, and for every inch of waterfall width, just as a quick calculation.
Lots of times the remaining flow was not even positive ;~).

A comment on your biological vs mechanical filtration attributes. From
my understanding, the characteristic of catching organic matter actually
falls under 'mechanical' filtration. Also the removal of visible
particulates comes under mechanical. Biological filtration is the
'warehousing' of the nitrifying bacteria to remove ammonia, nitrites and
even to some extent nitrates. Your description and advice were bang-on,
but the I think that the conventional description would be that they are
poor biological filters and only coarse mechanical filters. The
attribute to make them better mechanical filters (better water polishing)
is a tighter weave of sponge media, which also has more surface area,
more bacteria and is a better biological filter.

thanks again for shedding that UV light on me ;~)
--
www.NetMax.tk