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Thread: Sunlight...natural dechlorination???

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    Sunlight...natural dechlorination???

    I have a reasoable size pool (32'x32'x 5' deep) and need to drain it.
    I have left it for about 3 weeks with no chemicals added, I have kept the pump going (to keep the water flowing) and have had constant sunshine (Caribbean) as well as heavy rains.....

    I was told that it takes about a week to dechlorinate enough to allow draining into the ocean...?

    Can anyone advise?

    Many thanks!!

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    Mod Squad Bama Rambler's Avatar
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    Re: Sunlight...natural dechlorination???

    If you're draining it into the ocean I wouldn't think it'd need to dechlorinate at all. The order of magnitude difference would make the little bit of chlorine completely irrelevant.

    However, a week should have the chlorine very near zero if not zero.
    Dave J. TFP Moderator
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    Re: Sunlight...natural dechlorination???

    Many thanks!

    Based on that scenario.....would I be able to store water from the backwash into a contaier for use on the garden some days later?? Or could I just add it directly to my 4000gal rainwater tank and dilute it?

    Thanks again!

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    Mod Squad Bama Rambler's Avatar
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    Re: Sunlight...natural dechlorination???

    Most of us backwash our pool water directly on the lawn. I haven't noticed any ill effects. However we get about 60" of rain a year so in very dry areas things might be different.
    Dave J. TFP Moderator
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    solarboy's Avatar
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    Re: Sunlight...natural dechlorination???

    As long as it's not a salt water pool I don't see why not. I think if watering trees and shrubs you could probably get away with it straight out of the pool as on it's way to the plants roots it'll come across enough organics to use up all the chlorine. I wouldn't do it for too long in one place though.
    Self built 5500 gallon bare concrete (temporarily) pool with limestone coping, Pentair Swimmey 1/2 HP pump, Triton sand filter with DE, Simpool peristaltic muriatic acid pump with pH sensor and Monarch SWG. Home made solar heater with Pentair Compool control panel and 3 way valve. 1 skimmer, 1 main drain, 2 returns, 2" plumbing, Hayward auto fill valve.

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    Re: Sunlight...natural dechlorination???

    Don't forget that most water districts used to use chlorine (some now use monochloramine) at around 1 ppm or so and this was used for watering lawns, plants, etc.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
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    Re: Sunlight...natural dechlorination???

    My Neighbor has a salt pool, is there anyway he can filter out the salt / backwash to use on the garden?

    Someone said about filtering thru a sponge or secondary pool filter of some sorts|??

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    svenpup's Avatar
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    Re: Sunlight...natural dechlorination???

    The salt is in solution and can't be "filtered" out. If a filter could remove salt then it would be impossible to have a salt water pool. The only way to remove it is with reverse osmosis which is probably not practical for this application.
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    Re: Sunlight...natural dechlorination???

    Many thanks for all the input..

    i know we went slightly off thread but last comment on the intersting topic of re-using backwash water....!!

    If my pal back washes (salt pool) into a small holding tank, then drains off the water thru a filter (DE?) to trap the debris...can the salt solution thats left be returned to the pool??

    Thanks again!

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    JasonLion's Avatar
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    Re: Sunlight...natural dechlorination???

    I don't understand why you say "salt solution thats left". Is there any salt involved that wasn't in the pool in the first place?

    Assuming that "salt solution" is a simple mistake and you actually meant the pool water left in the holding tank, then the answer depends on what kind of holding tank is being used. Less expensive holding tanks often allow metals and possibly other debris to get into the water. Unless the holding tank was designed for use with drinking water I would not put anything that was in it back into the pool.
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    Re: Sunlight...natural dechlorination???

    Sorry.....i have confused the issue!

    Basically, if I backwash and send the BW water into a large plastic tank...could I then drain off the water thru a filter (cartridge?) to trap the dirt etc and leave the "salt solution / pool water" to flow back into the pool, which is now (in theory) free of debris & muck?


    Sorry to be pain in the A***....I'll get the beers in.......!

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    Mod Squad Bama Rambler's Avatar
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    Re: Sunlight...natural dechlorination???

    That certainly would work but it's a lot of trouble unless you're water restricted or water rates are extremely high where you are.

    I guess my big question would be. Why not just replace the current filter with a cartridge filter and not have to worry about backwashing?
    Dave J. TFP Moderator
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    Re: Sunlight...natural dechlorination???

    I did think of that see sand-or-cartridge-filter-t27025.html

    And yes, my pool is in an area of VERY high water rates!

    Gives me lots to sleep on, thanks all for your great advice!

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