Become a TFP Supporter Pool Math Forum Rules Pool School
Page 1 of 2 12 LastLast
Results 1 to 20 of 32

Thread: Partial drain

  1. Back To Top    #1

    Partial drain

    I am wondering if I need to do a partial drain on my pool opening or not. I had a cover on that allowed sunlight and water through over the winter. I took the cover off today and it is a total swamp. I can barely see 3 to 4 feet down. Should I just get my pH right and then start shocking the snot out of the pool, or should I drain a bunch of the water and then refil. I am not worried about the cost of the water as I have a well.
    16 x 38 inground pool, 20K gal, vinyl liner, 0.75 HP Hayward Superpump (SF 1.0, 115 V), Hayward Pro Serier Top Mount 24" sand filter (300lbs sand) with 62GPM design flow fate and 3.1 sq ft effective filtration area, Kreepy Krawly cleaner

  2. Back To Top    #2
    Mod Squad woodyp's Avatar
    Join Date
    Apr 2010
    Location
    East Texas
    Posts
    8,997

    Re: Partial drain

    That question can be better answered if you give us what your CYA level is. Got a good test kit--------or a pool store nearby for a water sampling?
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
    2 Speed Hayward Power-Flo Matrix 85 g.p.m. 22" 250lb. sand filter hard plumbed
    Pool Rover Jr., Pool Blaster Max, Diver Dave TF100 Test Kit/Speed Stir
    Margaritaville Frozen Concoction Maker, Liqour Chiller, & Drink Mixer & Party Tub----Collect 'um all!

  3. Back To Top    #3
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Partial drain

    To expand on what woodyp was saying, you want PH and TA somewhere plausible before you start shocking. If CYA is high you many need to lower it before shocking. If CYA is too low you want to raise it up to around 30 at the same time that you start shocking.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  4. Back To Top    #4

    Re: Partial drain

    I can appretiate what you guys are saying. I think I understand that if the CYA level is too high I will need to lower it by draining the pool and putting more water in to dilute the CYA levels.
    My real question is whether or not it would be better to pump out the algae water and then refil with clean water or if it would be better to just shock the algae water I have now.
    I am not sure how much it will cost to shock the water I have now into swimable stuff, but I think it will be quite a bit.
    16 x 38 inground pool, 20K gal, vinyl liner, 0.75 HP Hayward Superpump (SF 1.0, 115 V), Hayward Pro Serier Top Mount 24" sand filter (300lbs sand) with 62GPM design flow fate and 3.1 sq ft effective filtration area, Kreepy Krawly cleaner

  5. Back To Top    #5
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Partial drain

    A drain and refill will also cost something, quite possibly more depending on what you pay for water, and has a significant risk of damaging or destroying the vinyl liner.

    Shocking is the way to go.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  6. Back To Top    #6

    Re: Partial drain

    I don't pay for water. I have a well. But I don't want to risk damaging or destroying the vinyl liner.
    Does letting the water out somehow hurt the vinyl liner?
    16 x 38 inground pool, 20K gal, vinyl liner, 0.75 HP Hayward Superpump (SF 1.0, 115 V), Hayward Pro Serier Top Mount 24" sand filter (300lbs sand) with 62GPM design flow fate and 3.1 sq ft effective filtration area, Kreepy Krawly cleaner

  7. Back To Top    #7

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,082

    Re: Partial drain

    Does letting the water out somehow hurt the vinyl liner?
    Almost always. It will usually wrinkle and you WONT be able to get it back in place.

    You will have virtually just as much algae in the pool if you drain and refill as you do now. It grows very fast.

    So, if you decide to drain, then you will likely have an algae laden pool with wrinkles in the liner.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  8. Back To Top    #8

    Re: Partial drain

    This morning I can see a lot of algae on the bottom of the pool. Should I just let the shock get this, or should I vaccum it out of the pool and then refil the water I lose.
    16 x 38 inground pool, 20K gal, vinyl liner, 0.75 HP Hayward Superpump (SF 1.0, 115 V), Hayward Pro Serier Top Mount 24" sand filter (300lbs sand) with 62GPM design flow fate and 3.1 sq ft effective filtration area, Kreepy Krawly cleaner

  9. Back To Top    #9
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Partial drain

    Anything you can vacuum out easily is worth doing. The fact that the water is clear enough to be able to see near the bottom is a very good sign.

    Liners also shrink a little when you drain, and they sometimes tear when stretching back out, especially if they are more than a couple of years old.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  10. Back To Top    #10

    Re: Partial drain

    Thank you guys so much. You have already saved me a ton of heartache!
    16 x 38 inground pool, 20K gal, vinyl liner, 0.75 HP Hayward Superpump (SF 1.0, 115 V), Hayward Pro Serier Top Mount 24" sand filter (300lbs sand) with 62GPM design flow fate and 3.1 sq ft effective filtration area, Kreepy Krawly cleaner

  11. Back To Top    #11

    Re: Partial drain

    I got the pool up and running. Much of the algae on the bottom was pumped out to waste.
    I started out at 4pm by putting in 4 gallons of shock. Within 15 minutes the shallow end looked sooooooooooo much better.
    Anyways, before adding the shock, I got numbers from my pool store:
    Chlorine = 0
    pH = 7.3 (my test at home said 6.8, but maybe I am not good enough at distinguishing the shades of colors)
    TA = 160

    They would not test the CYA as they said it was too cold to get an accurate reading.
    They told me with my pH at 7.3, the would add some soda ash to get the pH up a bit first.
    16 x 38 inground pool, 20K gal, vinyl liner, 0.75 HP Hayward Superpump (SF 1.0, 115 V), Hayward Pro Serier Top Mount 24" sand filter (300lbs sand) with 62GPM design flow fate and 3.1 sq ft effective filtration area, Kreepy Krawly cleaner

  12. Back To Top    #12
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Partial drain

    PH at 7.3 is just fine, especially with the TA being a little high. The PH will tend to come up over time, no need to rush that process along.

    I'd start adding about 20 ppm of CYA, just to make sure that you have some CYA in the water.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  13. Back To Top    #13

    Re: Partial drain

    Ok, I learned a big lesson here.
    I drained my pool a bit way back in October when closing my pool. I covered it with one of those mesh covers that let water through. I thought I needed to let the water below the skimmers a good bit. Now that I am looking, the vinyl has wrinkled in more than a few placed. I hope this does not spell trouble.
    Also, I have now added 12 gallons of shock and my pool is looking much better, but I have yet to get a FC reading higher than 1ppm.
    16 x 38 inground pool, 20K gal, vinyl liner, 0.75 HP Hayward Superpump (SF 1.0, 115 V), Hayward Pro Serier Top Mount 24" sand filter (300lbs sand) with 62GPM design flow fate and 3.1 sq ft effective filtration area, Kreepy Krawly cleaner

  14. Back To Top    #14

    Re: Partial drain

    I am now hoping I did not screw things up.
    I added 4 gallons of shock at 4pm. Rechecked things at 5pm and got a Cl of 0.5. I added another 4 gallons of liquid shock. Rechecked at 6pm and got a Cl of 1.0. Added another 4 gallons of liquid shock. Rechecked at 7pm and got a Cl of 2.0. Added another 4 gallons of shock. I waited until 10pm to check again, thinking I would have to add more shock, but I ran out of reagent when I had added 95 drops. So the Cl level of free and combined is at least 47.5, could be higher. Maybe I needed to wait longer in between adding shock and checking the levels?
    16 x 38 inground pool, 20K gal, vinyl liner, 0.75 HP Hayward Superpump (SF 1.0, 115 V), Hayward Pro Serier Top Mount 24" sand filter (300lbs sand) with 62GPM design flow fate and 3.1 sq ft effective filtration area, Kreepy Krawly cleaner

  15. Back To Top    #15
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Partial drain

    Allowing an hour for the bleach to mix in before re-testing is fine, however adding 4 gallons of liquid shock each time was probably too much to be adding at one time.

    Do you have any idea what your CYA level is? If your CYA level is low then 4 gallons was way way too much to be adding at one time, while if your CYA is rather high then it doesn't matter so much.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  16. Back To Top    #16

    Re: Partial drain

    The guy at the pool store told me my CYA should not be tested because it is too cold outside. I wish I knew what my CYA level was. Last year it was about 60
    16 x 38 inground pool, 20K gal, vinyl liner, 0.75 HP Hayward Superpump (SF 1.0, 115 V), Hayward Pro Serier Top Mount 24" sand filter (300lbs sand) with 62GPM design flow fate and 3.1 sq ft effective filtration area, Kreepy Krawly cleaner

  17. Back To Top    #17

    Re: Partial drain

    I found out my problem. I was using my basic Taylor testing kit, but instead of using the correct R-0600 reagent, I was using the R-0003 from my FAS-DPD test. I used the R-0003 for the first four readings. Then on my last reading, I used the correct R-0600.
    Today when I looked again at the Cl using the basic Taylor kit, I just got a very dark organge color. Any idea how long with will take all this Cl to get out of the system? I did put in 16 gallons of shock in one day.
    16 x 38 inground pool, 20K gal, vinyl liner, 0.75 HP Hayward Superpump (SF 1.0, 115 V), Hayward Pro Serier Top Mount 24" sand filter (300lbs sand) with 62GPM design flow fate and 3.1 sq ft effective filtration area, Kreepy Krawly cleaner

  18. Back To Top    #18
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Partial drain

    Dark orange on the OTO chlorine test (normally shades of yellow) means TC is between 15 and 30. More of a brown color means TC is above 30.

    If CYA is around zero, then the chlorine will all go away today, even if it is cloudy. If CYA is still around 60 from last year, then perhaps two days.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  19. Back To Top    #19

    Re: Partial drain

    I checked the Cl again last night and with the basic Taylor test, I am still getting a dark organge to brown color. I am begining to think I put in enough Cl for the whole year!!
    16 x 38 inground pool, 20K gal, vinyl liner, 0.75 HP Hayward Superpump (SF 1.0, 115 V), Hayward Pro Serier Top Mount 24" sand filter (300lbs sand) with 62GPM design flow fate and 3.1 sq ft effective filtration area, Kreepy Krawly cleaner

  20. Back To Top    #20

    Join Date
    May 2010
    Location
    Southern Indiana
    Posts
    84

    Re: Partial drain

    Quote Originally Posted by jordangregory
    Post Posted: April 30th, 2011, 10:09 pm
    Reply with quote
    I am now hoping I did not screw things up.
    I added 4 gallons of shock at 4pm. Rechecked things at 5pm and got a Cl of 0.5. I added another 4 gallons of liquid shock. Rechecked at 6pm and got a Cl of 1.0. Added another 4 gallons of liquid shock. Rechecked at 7pm and got a Cl of 2.0. Added another 4 gallons of shock. I waited until 10pm to check again, thinking I would have to add more shock, but I ran out of reagent when I had added 95 drops. So the Cl level of free and combined is at least 47.5, could be higher. Maybe I needed to wait longer in between adding shock and checking the levels?
    Don't know if this is relevant or not, but this week I have been going through pool opening, shocking, etc., and during the FC test, the color change after adding the powder takes much longer to appear than in the summer - presumably due to cold water (about 58 F); then, immediately after adding the reagent drop(s), the water turns clear, but then slowly becomes pink again. If I had been a little hasty, and not waited to see if the pink color returned, I would have obtained a much lower FC reading. As it was, I obtained a reading more than double what an initial look indicated. jordangregory, is it possible your early FC readings were too low - were you waiting long enough to make sure the pink didn't return before obtaining your reading? Jason, chemgeek, etc., am I all wet on this?
    25 K gal, vinyl, IG, next to forest,liquid chlorine and tab chlorinator backup,55gpm sand filter,1.5hp pump

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •