Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 13 of 13

Thread: First test with new kit

  1. Back To Top    #1

    Join Date
    Aug 2015
    Location
    Georgia
    Posts
    17

    Post First test with new kit

    Been testing water at pool store and at home with basic pH/chlorine test kit, my Taylor 2006 test kit came in today. We built our pool 10 years ago and was chlorine for first 5 and salt generator for last 5 years, been much easier to maintain with the salt. Our pool is Gunite 16x32 with 3.5ft shallow end and 6.5ft deep end, pool builder says about 17K gallons. Our pool is screened in and stays about 5-10 degrees cooler than neighbors that aren't shaded, I've put a solar blanket over it this summer to warm it up a little.

    I recently had what appear to me to be black algae spots along one side, this is same side that had some light green dust like material in the corners. My wife says the trouble is from the increased shade from the solar blanket. I decided to take better control of the chemicals in the pool and order a quality kit. I tested the water with the kit and also took some water to pool store for comparison, they have a nice computer system that they put the water in a centrifuge type device.

    My Taylor test results Store results
    pH 7.4-7.5 7.6
    FC 1.8ppm 1.3ppm
    CC 2.0ppm 1.67ppm
    Alk 30ppm 35ppm
    Cal 290ppm 236ppm
    CYA <30 6
    Copper .1
    Iron .1
    Salt 3000

    Store said everything was OK but needed stabilizer, I bought a jug and told me to add half today and half tomorrow. Said chlorine and everything else was OK, I thought should try to get chorine up a little.

    We have no ladder or anything in the pool, the only metal is the ring around light and it looks terrible, dark rusty color and not smooth. I have had several small rust appearing lines in the bottom of pool over the last several years. They look like rust lines from the metal ties that rebar is secured with under the Gunite. I've wondered if its where the unite might be thin and rusting through. Pool installer looked at them and say looks like where something was dropped in pool like and nail and rusted. I disagree because nothing has ever been in our pool like that.

    I recently discovered this forum and was wanting some opinions on how my pool is doing. Is there anything else I should check/change?
    Thanks

  2. Back To Top    #2
    Mod Squad JVTrain's Avatar
    Join Date
    Feb 2014
    Location
    Central Minnesota
    Posts
    5,079

    Re: First test with new kit

    Quote Originally Posted by RedDmax View Post
    Been testing water at pool store and at home with basic pH/chlorine test kit, my Taylor 2006 test kit came in today. We built our pool 10 years ago and was chlorine for first 5 and salt generator for last 5 years, been much easier to maintain with the salt. Our pool is Gunite 16x32 with 3.5ft shallow end and 6.5ft deep end, pool builder says about 17K gallons. Our pool is screened in and stays about 5-10 degrees cooler than neighbors that aren't shaded, I've put a solar blanket over it this summer to warm it up a little.

    I recently had what appear to me to be black algae spots along one side, this is same side that had some light green dust like material in the corners. My wife says the trouble is from the increased shade from the solar blanket. I decided to take better control of the chemicals in the pool and order a quality kit. I tested the water with the kit and also took some water to pool store for comparison, they have a nice computer system that they put the water in a centrifuge type device.

    My Taylor test results Store results
    pH 7.4-7.5 7.6
    FC 1.8ppm 1.3ppm
    CC 2.0ppm 1.67ppm
    Alk 30ppm 35ppm
    Cal 290ppm 236ppm
    CYA <30 6
    Copper .1
    Iron .1
    Salt 3000

    Store said everything was OK but needed stabilizer, I bought a jug and told me to add half today and half tomorrow. Said chlorine and everything else was OK, I thought should try to get chorine up a little.

    We have no ladder or anything in the pool, the only metal is the ring around light and it looks terrible, dark rusty color and not smooth. I have had several small rust appearing lines in the bottom of pool over the last several years. They look like rust lines from the metal ties that rebar is secured with under the Gunite. I've wondered if its where the unite might be thin and rusting through. Pool installer looked at them and say looks like where something was dropped in pool like and nail and rusted. I disagree because nothing has ever been in our pool like that.

    I recently discovered this forum and was wanting some opinions on how my pool is doing. Is there anything else I should check/change?
    Thanks
    Welcome to TFP!

    Trust your Taylor results over pool store testing, especially the computer based testing.
    Is the CC number actually CC (combined chlorine) or the TC (total chlorine = FC + CC)? If that is CC, any time you have CC at 1 ppm or above, you need to SLAM the pool. See the link in my signature.

    Here at TFP we recommend higher levels of CYA for SWG chlorinated pools as it allows your FC to be shielded properly from sunlight (UV light) and allows your SWG to be able to maintain adequate chlorine levels with less run time, less % output on the SWG. Please see the the CYA/Chlorine chart in my signature for our recommendations there. In Georgia, I'd certainly recommend a CYA of 70 ppm to start and monitor your FC levels versus SWG output.

    Your alkalinity (TA) is low, which might lead to problems with pH bouncing around erratically when you need to adjust pH. I'd suggest bumping that TA up to 60 ppm and see how your pH responds. SWG systems are a source of aeration so lowish (60-80 ppm) TA levels are recommended. See the recommended levels for all other levels other than CYA/FC in this chart. Pool School - Recommended Levels

    The rust may we be rebar coming out through the gunite from rebar if it's close to the surface. If you input all your numbers into Pool Math (see link at the top of the page) you can see that your resulting CSI number is about -0.82 depending on actual temperature. Anything less than -0.6 for CSI is an indication of a corrosive environment for plaster pools. This could lead to erosion of your plaster surface and contribute to the appearance of shallow rebar. It may also be a problem for your metal light ring, but I'm not entirely well versed in CSI and how it affects metal corrosion. Low pH can certainly cause metal corrosion.

    If you were to up your TA to 60, CH to 350, CYA to 70 and maintain a pH near 7.8, you can see that your CSI number would be at about -0.11. This is certainly a safer CSI range to operate your pool and will not risk plaster corrosion.

    - - - Updated - - -

    Also, update your forum signature with details about your pool. It helps immensely for experts and other users to quickly see what kind of pool you're dealing with and give better advice.
    Joel - TFP Moderator - Minnesota - **Become a TFP Supporter!** Helpful Links: ABCs of Pool Water Chemistry - SLAM Procedure - Chlorine/CYA Chart
    40x20 Pool: 32K Gallons * Vinyl * Bleach Chlorination * Hayward S270T Sand Filter * Pentair SuperFlo 1 HP * Teledyne/Laars Heater * AquaVac Tigershark * TF-100 w/ SpeedStir
    Isolated Spa - 345 Gallons

  3. Back To Top    #3

    Join Date
    Aug 2015
    Location
    Georgia
    Posts
    17

    Re: First test with new kit

    I typed the chlorine in wrong, my CC was .2ppm, the TC was 2.0ppm using my test kit. From store the FC was 1.36 and Total was 1.67. My CYA was 6 from the store, it didn't show up on the post the way it did when I wrote it, had them separated by many spaces. My water temperature is 86 right now, I went and looked when doing the pool math calculations you suggested. I will add the required baking soda (120oz weight) to get the TA up. I guess that I go to the pool store to get product to raise the CH? Is the goal to get the CSI to 0.0? Thanks for all the help/info. I've learned more today about pool chemistry than in 10 years of ownership. I will get the my pool info and add to my signature tomorrow.

  4. Back To Top    #4
    Mod Squad pooldv's Avatar
    Join Date
    Aug 2012
    Location
    DFW, TX
    Posts
    23,994

    Re: First test with new kit

    No, don't raise your CH right now. Test your fill water first. It will likely creep up some more and it isn't all that low anyway.

    Here is a good resource, Pool School - Water Balance for SWGs
    TFP Moderator
    If TFP helped you or saved you money - Become a TFP Supporter! <--Click here
    2012 build and pics, 20k gal gunite, black onyx pebblesheen, OK flagstone, IntellifoVS, cart filter w/Pleatco, IC40 SWG, Solartouch, 5 12'x4' solar panels, HP50HA heat pump, 8mil solar cover, borates, TF-100 test kit, SONOS, Doheny's Discovery Robot, hot tub on bleach

  5. Back To Top    #5

    Join Date
    Aug 2015
    Location
    Georgia
    Posts
    17

    Re: First test with new kit

    Thanks, I will add the baking soda, some bleach and turn up my SWG tonight. I will recheck the numbers tomorrow afternoon and post results. I haven't had to add water in awhile, we are near Florida and been getting a fair amount of rain. When I do add water to pool it is from a well.

  6. Back To Top    #6
    Mod Squad pooldv's Avatar
    Join Date
    Aug 2012
    Location
    DFW, TX
    Posts
    23,994

    Re: First test with new kit

    Test the well water for PH, TA and CH. Also, do you know if there is iron in your well water?
    TFP Moderator
    If TFP helped you or saved you money - Become a TFP Supporter! <--Click here
    2012 build and pics, 20k gal gunite, black onyx pebblesheen, OK flagstone, IntellifoVS, cart filter w/Pleatco, IC40 SWG, Solartouch, 5 12'x4' solar panels, HP50HA heat pump, 8mil solar cover, borates, TF-100 test kit, SONOS, Doheny's Discovery Robot, hot tub on bleach

  7. Back To Top    #7

    Join Date
    Aug 2015
    Location
    Georgia
    Posts
    17

    Re: First test with new kit

    Sorry didn't post results up the next day, spent the whole weekend with a fever in the bed. Can't remember the last time that I've been sick in the bed for a single day especially three days. Checked the pool this evening and the numbers are as follows:

    FC 5.4
    CC .2
    pH 7.7
    TA 60
    CH 300
    CYA <30 still

    I added the other half of the 6 lb jug of dry stabilizer this evening. How long before the CYA will start to show up? I was told always told to never have the pH up (in the pink/red) and have high chlorine, that it would damage my finish. Is that correct? I was planning on adding acid to keep near 7.5 but was told on here to keep near 7.8. According to my inputs I have a CSI of -.13 right now ,should I leave things alone. I did get a metal brush this evening and brushed the spots that look like may be black algae spots.

  8. Back To Top    #8

    Join Date
    Aug 2014
    Location
    Northern IL
    Posts
    4,615

    Re: First test with new kit

    BTW, use a 10 ml sample to test your FC/CC and multiply by 0.5. You will save on reagents that way.

    Search fingernail test black algae to confirm.

  9. Back To Top    #9

    Join Date
    Aug 2015
    Location
    Georgia
    Posts
    17

    Re: First test with new kit

    I will get in the water and do the fingernail test tomorrow evening, I'm pretty convinced it is black algae. I may need to read up on the SLAM I've heard about but never done. I guess this is a good time since my CYA is pretty much nonexistent as this point.

  10. Back To Top    #10
    Mod Squad pooldv's Avatar
    Join Date
    Aug 2012
    Location
    DFW, TX
    Posts
    23,994

    Re: First test with new kit

    TFP Moderator
    If TFP helped you or saved you money - Become a TFP Supporter! <--Click here
    2012 build and pics, 20k gal gunite, black onyx pebblesheen, OK flagstone, IntellifoVS, cart filter w/Pleatco, IC40 SWG, Solartouch, 5 12'x4' solar panels, HP50HA heat pump, 8mil solar cover, borates, TF-100 test kit, SONOS, Doheny's Discovery Robot, hot tub on bleach

  11. Back To Top    #11

    Join Date
    Aug 2014
    Location
    Northern IL
    Posts
    4,615

    Re: First test with new kit

    Perfect time to SLAM!

  12. Back To Top    #12

    Join Date
    Aug 2015
    Location
    Georgia
    Posts
    17

    Re: First test with new kit

    Going to SLAM it starting tonight. Even if the spots aren't black algae I still get a pale green dusting in the corners/shaded spots. Just checked pH 7.4 and FC 9.5, CC .5 How hight do I want to get my FC with the SLAM? The chart for SWG starts at CYA of 60 and a Shock FC of 24. I'm showing CYA of less than 30 with the test so don't really know a number. I was going to get the FC up to 15-18? That's just me guessing where I should try and reach. I've had my SWG turned up to 80% for 2 days, going to put it on boost and add bleach.

  13. Back To Top    #13

    Join Date
    Aug 2014
    Location
    Northern IL
    Posts
    4,615

    Re: First test with new kit

    Nope. For a SLAM, turn off your SWG. Assuming 30 CYA, your SLAM level is 12.

    Please reread Pool School - SLAM - Shock Level And Maintain

    The most frequent mistake is the process is not keeping (maintaing) your FC at shock level or a bit above.

    With SWG off, use the non-SWG shock values.

Posting Permissions

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