water loss from overflow pool

[timefore]

Can anyone give advice on water loss due to evaporation - we have a 10 x 5 overflow pool and would be interested on what sort of loss we should expect?

[TRNCVaughan]

Between 30% and 50% per annum.

[madamx]

But you may get a lot more!

[sophie]

Because of where we are situated i.e. the pool is very close to the edge of a ravine and there is a constant cross wind (or srongish breeze even in the height of summer with nothing to protect it) we reckon it can easily be 50% or perhaps more. BTW, this is definitely through evaporation and not leakish. We don't always keep ours in overflow, to help lessen evaporation.

[thornaby]

Hi Sophie
I guess you are coming off overflow to allow you to drop your level in the hope it will reduce your evaporation due to your cross winds?
Please remember that the top 150 m.m. of water contain 75% of the pools total bacterial contaminates.
The pool I maintained in the u.k. was a hydrotherapy pool in a large hospital (the water was that clean you could have swam in it).
We ran that with the overflow (balance tank) valve fully open and the "drain" valve partially open.
So most of the filtration was from the top layer of the pool water and a small amount from the pool bottom.
O.k. no outside contaminates, industrial size pumps that ran 24/7 and a sand filter big enough to house 20 eastern Europeans!
Happy days!

[pc4854]

Also be aware that water can be leaking under the coping stones, so check them regularly and also the seal on the plastic runners that the grills sit on, if that is perished water can escape down there too.

[thornaby]

Its like so mutch of the work here, built to poor standards.
Do it right in the first place and hopefully you will not need to revisit it, spending yet more money!

[sophie]

I'll take that on board Thornaby. I forgot to say that the coping stones can get b**y hot and of course the water evaporates more as it flows over them A bit of an expensive luxury methinks. Still haven't ventured in. Last in, first out, that's me!!

[thornaby]

Sophie the waters fine come on in!

[brian24001]

Also worth remembering that concrete is very porous, if your gulley isn't tiled (I have seen many in NC that are not), you can save water there, but more importantly, mould etc is less likely to grow as there is no continuously damp area in the gulleys.