On Sun, 10 Sep 2006 11:48:24 GMT, Lobster wrote:

Wouldn't there be a likelihood that contamination in the harvested
water - ie assorted bits of crud which it would undoubtedly contain -
would damage/clog up valves, prevent float valves from seating
properly?

Assuming ther orginal source of water is the roof, yes it will contain
"bits" but most will settle out in the primary collection tank. The fill
rate of conventional 3 to 4' high, diverter fed, top filled water butt
isn't enough to disturb the sediment. Take the pump feed 6" above the
bottom and through a coarse filter so as not "suck up" the sediment(*)
and I think very little will find it's way to the loft tank. Up in the
loft tank it can settle again with the outlet a little above the base.

Finding a pump that doesn't have to high a flow rate, thus stiring either
the lower or upper tank might be fun. Also automatic (if required) change
over between mains and harvested water might be fun and you really do not
want any back siphonage of harvested water into the mains...

(*) Perhaps arrange the feed through a short upstand of pipe with filter
element on the sides rather than the end.

--
Cheers
Dave. pam is missing e-mail