Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 10 of 10

Thread: How deep?

  1. Back To Top    #1
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    15,422

    How deep?

    How deep should I draw my test sample?
    Taylor test kits say
    7. Obtain samples 18" below water surface.
    TF Test kits say
    6. Collect all your pool water samples about a foot under the surface.
    I understand that the surface water is going to have oils and pollen and such which could affect the tests. I've been using a piece of PVC pipe like a pipette and draw the sample from a couple inches off the floor in the shallow end, maybe 30" below surface. What's the difference between 12", 18", and 30" from the top? Do the chemicals stratify or something?
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  2. Back To Top    #2
    mas985's Avatar
    Join Date
    May 2007
    Location
    Pleasanton, CA
    Posts
    9,918

    Re: How deep?

    It shouldn't matter too much as long as you take a sample while the pump is running or shortly there after. If the water has been idle for too long then there could be some difference by depth, especially on a hot sunny day. I usually will just go a foot down with an upside down bottle, turn it right side up to take the sample but half way or more into the pump cycle.
    Mark
    Hydraulics 101; Pump Ed 101; Pump and Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, 1/2 HP 2sp pump, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

  3. Back To Top    #3
    polyvue's Avatar
    Join Date
    Aug 2009
    Location
    Sacramento, California USA
    Posts
    1,215

    Re: How deep?

    Quote Originally Posted by Richard320
    How deep should I draw my test sample?
    Taylor test kits say
    7. Obtain samples 18" below water surface.
    TF Test kits say [quote:309fboyu]6. Collect all your pool water samples about a foot under the surface.
    I understand that the surface water is going to have oils and pollen and such which could affect the tests. I've been using a piece of PVC pipe like a pipette and draw the sample from a couple inches off the floor in the shallow end, maybe 30" below surface. What's the difference between 12", 18", and 30" from the top? Do the chemicals stratify or something?[/quote:309fboyu]Mark's answer makes sense to me. I think the only difference between test kit instructions is the author... Dave appreciates the fact that often "close enough" is... well, close enough. Taylor probably conforms to the aquatics industry standard. I've often seen papers that instruct you to fetch the sample "elbow-deep" (everyone knows that human forearms are all exactly the same length!)

    More commonly, the instructions I've read that apply to commercial pools place more emphasis on taking multiple area samples (deep end, shallow end and middle, for example) whose test results are averaged together to approximate the entire pool, and instructions that detail how samples should be capped (no air) and chemically treated for presumed off-site testing.
    14,555 gal in-ground 16'x29' white plaster Pool w/spa (2007); Goldline Aqua Logic AQL-PS-8 control w/Aqua Cell 15 Salt Water Chlorination (SWCG); Hayward TriStar 1HP (1.85 SF) main / 1.5HP (1.60 SF) spa pumps; Hayward Swimclear cart filter C4025, ColorLogic LED lights; Tankless SP-18-4 electric heater; Polaris 280 cleaner.
    __
    View of spiral galaxy in Ursa Major NGC6217 - Hubble Telescope 2009

  4. Back To Top    #4
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887

    Re: How deep?

    The one thing you don't want to do is to take a sample from right at the surface. There is a thin layer of water right at the surface that has had far more interaction with floating debris than the rest of the water in the pool has. Also, the top several inches of water have been affected by sunlight far more than the rest of the water has.
    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

  5. Back To Top    #5
    Ohm_Boy's Avatar
    Join Date
    May 2007
    Location
    Orlando, FL
    Posts
    1,344

    Re: How deep?

    I have always used "elbow depth" as a guide, but I really try to reach as deeply as I can without soaking my sleeve.
    [center:1kpalu48]Helpful Links: Pool School | CYA/Chlorine Chart | Pool Calculator[/center:1kpalu48]

  6. Back To Top    #6

    Join Date
    Feb 2008
    Location
    Flower Mound, TX
    Posts
    5,062

    Re: How deep?

    What OhmBoy said . Just make sure that the pump is circulating water.
    10K gallon IG gunite with waterfall; Pentair CC320P filter; WhisperFlo 2 HP pump
    TF Test Kits - Pool Math - Pool School
    "It depends."- JohnT

  7. Back To Top    #7
    New2Me's Avatar
    Join Date
    Jun 2008
    Location
    SW Indiana
    Posts
    322

    Re: How deep?

    All that wet work when it's cold out is no fun! If you have a Hayward off-line Automatic Chlorinator installed, then you install a tee and a little ball valve in the feed line. Then when ever the pump is running and you want to test the water, you open the valve, purge the line, then fill your bottle, easy-peasy! If you didn't have the chlorinator, you can just drill a hole and mount the valve. No dipping necessary!
    22 x 40 IG vinyl lined, 23,570 gal.
    1 hp. Pac-Fab Challenger pump 300# sand filter
    Intex 8110 SWG, Hayward CL220 offline feeder
    Hayward 250K Btu gas heater
    Aquabots

  8. Back To Top    #8
    Brentr's Avatar
    Join Date
    Oct 2009
    Location
    Jacksonville, FL
    Posts
    874

    Re: How deep?

    Quote Originally Posted by New2Me
    All that wet work when it's cold out is no fun! If you have a Hayward off-line Automatic Chlorinator installed, then you install a tee and a little ball valve in the feed line. Then when ever the pump is running and you want to test the water, you open the valve, purge the line, then fill your bottle, easy-peasy! If you didn't have the chlorinator, you can just drill a hole and mount the valve. No dipping necessary!
    Not sure if I would want to do any drilling into a perfectly good PVC pipe , but if that works for you go for it I would opt to stick my hand in the cold water
    5,775 gal, IG free form, Beach Series Antigua by Marbletite Pebble finish, 2 swim out benches, Sheer Descent, IG Fountain, Dolphin / Mermaid Statues, StaRite Dura- Glas 1.5hp pump, Hayward Pro Series Sand Filter replaced with Hayward Pro-grid DE4820, Aqua Rite SWG with T-Cell 15, Polaris 360, Pentair 300w Light upgraded to Pentair IntelliBrite (OMG what a huge difference) , Heat Siphon Heat Pump DX 5.0 109,000 btu, Pool Cage, 1800sq ft Tremron Estate Pavers, solar cover, TF-100 test kit, Pentair Deck Jet, Apollo Magnetic Stirrer (Makes testing a breeze), Aquatherm Ecosun Solar Panels 192 sq ft with GL-235 Controller,Margarita Concoction Machine,
    Pics of our Spool ( Social Pool) being built Solar install Outdoor kitchen upgrade

  9. Back To Top    #9
    Ohm_Boy's Avatar
    Join Date
    May 2007
    Location
    Orlando, FL
    Posts
    1,344

    Re: How deep?

    Keep a 4-foot length of PVC near the pool, and when you want to collect a sample, cover one end of the pipe with your hand, poke the other end into the pool to a foot or 18 inches or so, release the top end to allow the pipe to fill, then cover it again, lift and retrieve a sample 'slug' of water. Dump it into your sample container, and there you are/Bob's your uncle/boom goes the dynamite/presto!
    [center:1kpalu48]Helpful Links: Pool School | CYA/Chlorine Chart | Pool Calculator[/center:1kpalu48]

  10. Back To Top    #10
    Mod Squad zea3's Avatar
    Join Date
    Jul 2009
    Location
    Houston, Texas
    Posts
    7,570

    Re: How deep?

    I prefer a length of clear plastic tubing (like is used in aquariums) with a fishing weight attached to one end. I use a infant nasal aspirator to siphon water into the tube. Once the water is flowing, fill up your container. Most of the time the water is warm enough to just shove the bottle down elbow deep but if you don't want to stick your hand in it works great! It is also handy for having the vertically challenged family members get the sample from an above ground pool!
    TFP Moderator
    Helpful links: TF Test Kits,TFP Pool School, PoolMath
    Vogue 21' round AG, Pentair 1 hp 2 speed pump, 36 sq ft DE filter, Hayward S180T 150# sand filter, Houston, Texas
    Love TFP? Become a
    TFP Supporter!

Posting Permissions

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