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Thread: vacuum to waste vs backwash

  1. #1
    Senior Member TimS's Avatar
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    vacuum to waste vs backwash

    I've read several postings recommending that when fighting algae, you should vacuum to waste. I got to thinking about this yesterday while vacuuming my pool for the first time this year. Without getting too verbose on this one, why the recommendation to vacuum straight to waste instead of vacuuming to the filter and then backwashing?

    In my (very limited) experience, I lose a lot less water backwashing than I do vacuuming to waste. I also have a very bad habit of being very aware of all the water I'm dumping and rushing the job. Even though my water is very cheap, I still don't like throwing away more than I have to.

    Thanks,
    Tim.
    24' AG Round (vinyl replaced 0909) - 13500 gal - Sand Dollar Filter (150lb) - Dynamo DYNII-N1-1 1HP - Hayward HP380 Heat Pump - TF-100.
    Central Missouri

    Before I speak, I have something important to say.

  2. #2
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    Re: vacuum to waste vs backwash

    I don't use a sand filter, but my understanding is that some of the algae will pass through the filter and go back into the pool,and what the filter does catch will build up so fast you have to backwash quite frequently.

    Someone correct me if I'm wrong.
    John

    24' round Vogue AGP 12,000 gal. Flotec AT251001-01 1HP pump, Hayward S310T2 sand filter
    TF-100 (found at TF Test Kits) with Speedstir and Samplesizer

  3. #3
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    Re: vacuum to waste vs backwash

    More likely, the stuff you vaccuum up will clog the filter and reduce the flow to nothing, so you have to backwash in order to keep vaccuuming. Over and over.
    --paulr
    BBB "Intermediate Swimmer"
    IG plaster pool 18.5K gal, Hayward Pro-Grid DE filter, 3/4 HP Hydramax II; Polaris 380, 3/4 HP booster
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  4. #4
    Administrator JasonLion's Avatar
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    Re: vacuum to waste vs backwash

    If whatever you are vacuuming up is concentrated in a small area, so you can get lots of it without taking too much time, it is often worth vacuuming to waste. In practice, this doesn't happen all that often.

    If you vacuum a lot of algae out of the pool, and then fail to backwash, the algae is caught in the filter, where it can still grow and still consume chlorine. If you vacuum a bunch of algae to the filter, you should backwash afterwards.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    TFP Admin. Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  5. #5
    Senior Member TimS's Avatar
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    Re: vacuum to waste vs backwash

    When I raised the water level a couple of weeks ago, I only raised it far enough to get the equipment running. (Had to remove the weir from the skimmer, since the water level was so low. I was really only interested in circulation at that point.)

    Saturday, when I removed the cover and vacuumed the first time, I did vacuum straight to waste, but did it so quickly that I stirred quite a bit back up, and had to wait for it to settle again. At that point, I added more water, but didn't want to flush it all back out, so on Sunday, I vacuumed to the filter first, then immediately backwashed. It only took about 2 minutes to clear the filter, instead of the 10 minutes it took to vacuum on Saturday. I didn't bother to accurately measure the water level either time, and know that the flow through the vacuum hose is lower than the flow directly through the skimmer, but even so, it had to have used at least 50% less water to backwash.

    This all assumes that I actually got the filter clean

    Quote Originally Posted by JasonLion
    If whatever you are vacuuming up is concentrated in a small area, so you can get lots of it without taking too much time, it is often worth vacuuming to waste. In practice, this doesn't happen all that often.

    If you vacuum a lot of algae out of the pool, and then fail to backwash, the algae is caught in the filter, where it can still grow and still consume chlorine. If you vacuum a bunch of algae to the filter, you should backwash afterwards.
    So it's acceptable to vacuum to the filter, provided that you immediately clean the filter? (It would seem so to me, but I'm still pretty new at all this, even with one season under my belt.)

    Is the standard recommendation (vacuum to waste) more of a KISS thing trying to idiot-proof the process as much a possible?
    24' AG Round (vinyl replaced 0909) - 13500 gal - Sand Dollar Filter (150lb) - Dynamo DYNII-N1-1 1HP - Hayward HP380 Heat Pump - TF-100.
    Central Missouri

    Before I speak, I have something important to say.

  6. #6
    Administrator JasonLion's Avatar
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    Re: vacuum to waste vs backwash

    Vacuuming to waste is not the standard recommendation around here. I only recommend vacuuming to waste in extreme situations or when using floc (which I tend not to recommend). At the same time, there is nothing wrong with vacuuming to waste, as long as you don't mind losing a bunch of water.

    Other people recommend other things. There are many ways to approach the problem that all work.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    TFP Admin. Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

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