Swimming pool backwash-how often please?

batgirl


Joined: 04/02/2009
Posts: 676

Message Posted:
07/09/2011 12:40

Given the shortage of water and the cost of buying how often do you backwash and for how long? as it is advised every time after cleaning,is this not a waste?

Thanks

yrret


Joined: 17/08/2010
Posts: 761

Message Posted:
07/09/2011 12:58

bg,

You should have a pressure gauge on top of your filter which meassures any pressure increase at the top of the sand level. If the pressure goes up it is because the sand is becoming blocked, and so the system requires backwashing.

Anther easy to spot sign is if the water (at surface) above your inlet jets is not moving much then again the filter is becoming blocked and it's time to backwash.

By your miltvalve, there should be a small sight glass, backwash utnil this is clean, or of you can see the outlet pipe, check there, then always flush the system for about 10-15 seconds also.

batgirl


Joined: 04/02/2009
Posts: 676

Message Posted:
07/09/2011 16:37

Thanks for that advice ,anyone else with comments please.

keithcaley



Joined: 13/06/2008
Posts: 2521

Message Posted:
07/09/2011 17:01

Msg2 is quite right

As muck gets drawn thro' the filter, and lodges between the sand particles, the pressure gauge reading will rise

Oddly enough, until it seriously impedes the flow of water thro' the filter, this actually improves the filter-action

To determine the optimum point at which to backwash, note the pressure gauge reading intermediately after a backwash & when the reading has doubled, it's time to do it again

The filter bed does take a little while to settle down & form an effective filter after a backwash, so don't backwash immediately before vacuuming the pool, keep an eye on the pressure gauge & either do it the day before vacuuming, or straight after

Don't try to be TOO economical tho', if the backwash is overdue, there won't be enough suction at the vac head, & no matter how slowly and carefully you try to vac, the muck will float about instead of going up the vacuum tube

If you can afford it, get a separate tank to save your backwash water for the garden

keithcaley



Joined: 13/06/2008
Posts: 2521

Message Posted:
07/09/2011 17:20

I thought that I'd nicely squeezed all that in on one post, but I spotted a Typo: -

that bit should read "note the pressure gauge reading IMMEDIATELY after a backwash" not "intermediately" !

I blame this cheap second-hand Chinese spell-checker of mine...

Incidentally, if you do save backwash water, the chlorine will dissipate after a few days making it safe to use on the garden (quicker if open to the air and sunlight) - If the chlorine concentration is only in the region of 1 part per million, then it's fine anyway, & of course alternative chemicals like Zerochlor don't affect plants themselves, and generally require much lower levels of 'sanitizer' (such as chlorine)

If, for some reason the chlorine was excessively high (after 'shocking', for instance) then you might need to add a little ammonia to assist the breakdown of the chlorine, & use a test test kit to determine the level before re-use

That's also one way to reduce the pool chlorine level after 'shocking' if needed

Tango1


Joined: 19/02/2011
Posts: 1151

Message Posted:
07/09/2011 17:33

I agree with the messages above, you will know when its needed. HOWEVER, I have a friend whose pool cleaner insists that he does a back wash every time he cleans the pool (and it's a biggy). I've tried to persuade her to tell the cleaner he'd talking nonsense but she won't do it. I can't even bring myself to tell you how much delivered water she has a week. It's horrendous and would be sufficient for a small village on the Karpaz or wherever. I've often wondered if the cleaner was related to the water supplier??



T1

yrret


Joined: 17/08/2010
Posts: 761

Message Posted:
07/09/2011 18:02

T1 msg 6

suggest to her to get water from a different source to see if it changes.





BTW, for backwashing, and so you stop as soon as possible when it is clean, you can get glass sight chamber at the pool shopm opposite the ship, that way you see imediately when it's clean and stop the wasteful water.

The chamber fits into the backwash line close to the multi valve.

Been meaning to fit one myself for ages.

deputydawg


Joined: 30/03/2010
Posts: 1727

Message Posted:
07/09/2011 18:41

Once you know how to care for a pool it is easy but difficult to learn simply by following written advice as sound as that may be. You may wish to consider employing a proven competent pool cleaner permanently, or to teach you by practical demonstration over a period of time until you are confident and competent enough to enjoy doing it yourself. I really enjoy looking after my pool and get a great sense of satisfaction from being able to spot what needs doing and when plus of course enjoying to the full it's use with family and friends.

TRNCVaughan


Joined: 27/04/2008
Posts: 4578

Message Posted:
08/09/2011 10:50

Backwashing is needed only when the pressure gauge reads 10psi more than what it did immediately after the previous backwash.

Watch the sight glass on the MPV while backwashing and when it starts to run clear, stop the pump and switch to "rinse". Run pump for about 10-15 seconds, stop pump again and switch back to "filter".

NB Never operate the MPV while the pump is running.