On Fri, 26 Aug 2005 10:16:29 +0100, Holly, in France wrote:

Hamie wrote:

snip snip..

The water is improving
all the time, the flocculant seems to be the answer. I suspect that
a given amount of flocculant can only coagulate a certain amount of
particles, and that's why it continues to improve it.

Hmm..

When I used to maintain a pool back home flocculant was added at
night, and left to settle. The next day you vacuumed all the crud off
the bottom.

Thanks for that, you're quite right, I didn't explain in detail but that
is what we are doing. Last night's dose of flocculant has cleared the
water completely, we can actually see the bottom of the pool this
morning, but it will get stirred up again in a mintute by the vacuum,
see below.

Seems to me if you're trying to filter out the crud it will take even
longer (Because you vacuum straight to waste, wheras trying to filter
it you just crud up the filter & require frequent backwashing)

We are vacuuming the crud but our vacuum works off the main pool suction
line so the waste, apart from heavy particles which get collected in a
gadget on the cleaner hose, goes into the sand filter anyway. Then the
cleaner sort of judders/throbs as it goes and stirs up a fair bit that
it can't suck up, so this ends up in the water but does seem to get
filtered out eventually.

Ah, sounds like you're using an 'automatic' pool cleaner, like a creepy
krawly or similar. These are fine for on-going pool maintenance, just to
get rid of stray leaves and debris that fall or blow into the pool, and to
suck up any *thin* patches of dead algae, but they're not the thing to use
when your pool is heavily contaminated with debris.

I'm just off out now to try to guide the cleaner round to the worst
bits, since it goes at random and doesn't reach some areas, then I'll
leave it to it's own devices for a couple of hours.

You need to splash out (pardon the pun) on a suitable pole, a length of
vacuum hose, a suitable 'skim-vac' adaptor and either a liner or concrete
pool suction head, depending on the type of pool.

The 'skim-vac' adaptor merely sits over the top of the leaf basket in the
skimmer, fix the vacuum head onto the pole, join the adaptor plate to the
vacuum headplate with a length of vacuum hose, and feed the pipe into the
pool from the vacuum head upwards IYSWIM, to make sure you get most of the
air out of the pipe.

Fill the pool to the brim. Set the multiport valve on the side of the
filter to 'waste'. I'm assuming you've got a proper multiport valve - NEVER
alter it with the pump running, you'll tear the rubber diaphragm inside,
then you've got more expense.

Close the inlet valve from the sump and any other skimmers you might have,
start the pump, pop the skim vac plate over the skimmer basket and you have
maximum suction on the vacuum head. You then manually vacuum everything out
to waste, always keeping an eye on the water level. Takes me about an hour
to vacuum my pool when it's not too dirty! Again, there's no easy magic
wand way.

You might just have a separate vacuum point installed, the pipe goes
straight into this and you're then relying on the debris basket in the pump
rather than the skimmer to collect any large bits of debris, leaves, etc,
but you'll need to adjust the appropriate inlet valves adjacent to the
pump.

HTH.

It's promising to be a reasonable day here, shall probably be in mine this
afternoon - temperature is about 32°C.

--
the dot wanderer at tesco dot net