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

Thread: First TF-100 Test - What to do next?

  1. Back To Top    #1

    Join Date
    Aug 2016
    Location
    Houston/Texas
    Posts
    6

    First TF-100 Test - What to do next?

    Alrighty!

    Just got the Tf-100 in the mail today:

    FC: 6.5
    CC: 0.5
    TC: 7.0
    CH: 400
    TA: 80
    CYA: Almost 90
    Ph: 7.8

    Just bought the house (and the pool). The plaster has some brown stuff on it. Did the vitamin C test and it does clear up - trichlor test does nothing. Already did a 30% water change to lower CYA (prior to this test!).

    My thoughts are:

    1) Another water change to lower CYA
    2) SLAM pool until OCLT passes
    3) Balance the PH out with dry acid

    Does this sound reasonable or should I approach this differently?
    17,000 gallon gunite pool, Pentair FNSP60 DE filter, Century Centurion 2.6HP main, 0.75 HP Polaris PB4-60 Booster, Polaris 280

  2. Back To Top    #2
    needsajet's Avatar
    Join Date
    Jan 2016
    Location
    Sydney, NSW, Australia
    Posts
    3,552

    Re: First TF-100 Test - What to do next?

    Welcome to TFP! Good to have you here

    Note point #9 in this thread regarding CYA tests at 90 and above: Pool School - CYA
    If you do a diluted test, and get 40/50 ish, then your 90 is accurate enough. And yes, if you need to SLAM, drain again to take it down to 40ish.

    I'll go get a metals expert to come chip in regarding the iron, before you start the SLAM.

    I would use muriatic acid (liquid) for lowering pH, but I would leave it at 7.8 until starting the SLAM, then drop it down to 7.2 per the article: Pool School - SLAM - Shock Level And Maintain

    And just checking your reason for the SLAM. Is there algae or cloudiness? Did you raise the 6.5 ppm FC to target level for 90 ppm CYA?
    12k IG salt; glass beads in plaster; K-2006C, K-1766, CCL, and Aussie 4in1 (HTH); Pentair Eco800 1.2HP VS; Zodiac SWC 1.3 lb/day (25 g/hr); 25" filter recycled glass; OKU solar panels; 1/2 HP solar pump; Rebel (Warrior) pool cleaner; FlowViz; prior pool AG 10k | Read Before Posting to get the best possible advice | ... and this helped me a lot!: TFPC for Beginners

  3. Back To Top    #3
    needsajet's Avatar
    Join Date
    Jan 2016
    Location
    Sydney, NSW, Australia
    Posts
    3,552

    Re: First TF-100 Test - What to do next?

    People who really know their stuff here say SLAM first, treat the iron later. So SLAM starts after water replacement.
    12k IG salt; glass beads in plaster; K-2006C, K-1766, CCL, and Aussie 4in1 (HTH); Pentair Eco800 1.2HP VS; Zodiac SWC 1.3 lb/day (25 g/hr); 25" filter recycled glass; OKU solar panels; 1/2 HP solar pump; Rebel (Warrior) pool cleaner; FlowViz; prior pool AG 10k | Read Before Posting to get the best possible advice | ... and this helped me a lot!: TFPC for Beginners

  4. Back To Top    #4

    Join Date
    Dec 2014
    Location
    Santa Ana, CA
    Posts
    523

    Re: First TF-100 Test - What to do next?

    Quote Originally Posted by TexasYankee View Post
    Alrighty!

    Just got the Tf-100 in the mail today:

    FC: 6.5
    CC: 0.5
    TC: 7.0
    CH: 400
    TA: 80
    CYA: Almost 90
    Ph: 7.8

    Just bought the house (and the pool). The plaster has some brown stuff on it. Did the vitamin C test and it does clear up - trichlor test does nothing. Already did a 30% water change to lower CYA (prior to this test!).

    My thoughts are:

    1) Another water change to lower CYA
    2) SLAM pool until OCLT passes
    3) Balance the PH out with dry acid

    Does this sound reasonable or should I approach this differently?
    Can you start from OCLT? My thinking is if your water is clear and it seems you have iron stains you want to check your pool water and your fill water for iron to understand what to expect. If you're lucky and fill water has significantly less iron I'd try to 'lift' the stains in the water before the drain using iron sequestrant. This way you'd remove more iron from your pool during drain. Basically kill 2 birds and all that .
    44k plaster pool, Pentair 011018 pump, DE6020 filter, LED lights, K2006 test kit

  5. Back To Top    #5
    needsajet's Avatar
    Join Date
    Jan 2016
    Location
    Sydney, NSW, Australia
    Posts
    3,552

    Re: First TF-100 Test - What to do next?

    First up, waiting to hear why the SLAM is needed.

    Good idea from max above. You can sequester more iron before draining, so more goes out with the drain water. It comes in with your fill water, and builds up over time from water top-up. See this article: Pool School - Metals in the Water and Metal Stains
    12k IG salt; glass beads in plaster; K-2006C, K-1766, CCL, and Aussie 4in1 (HTH); Pentair Eco800 1.2HP VS; Zodiac SWC 1.3 lb/day (25 g/hr); 25" filter recycled glass; OKU solar panels; 1/2 HP solar pump; Rebel (Warrior) pool cleaner; FlowViz; prior pool AG 10k | Read Before Posting to get the best possible advice | ... and this helped me a lot!: TFPC for Beginners

  6. Back To Top    #6
    Swampwoman's Avatar
    Join Date
    Apr 2012
    Location
    Grand Rapids, MI
    Posts
    3,534

    Re: First TF-100 Test - What to do next?

    Good morning, Texas. Are you on well water, or is your municipal water source known to have iron?

    Is there any reason you need to slam? Eg. Do you have algae?

    Slamming and metals don't go well together...you can oxidize the metal and tint your water and cause further staining. If there is metal sequestrant in the water, slam/shock levels will also break it down prematurely.

    SO, if you DO absolutely need to slam, its best you do so first, then treat for metals after, which could also involve a stain treatment.

    But to figure out the best way forward, it helps to confirm the metal source if possible, get a idea of read, etc. --you may be replacing that water (which you do need to do to bring down the cya) but introducing more metal in doing so.

    So please post information about your water source, and even a picture of your staining might help (note..,it could also be copper so we need to try to rule a few things out or in as the case may be.)

    In the mean time, keep your FC at target according to te FC/CYA Chart chart at all times and consider doing an Overnight Chlorine Loss Test to confirm whether or not you need to slam. I'll check back in tonight.

    Congrats on your new pool!
    In ground extended Grecian, 22,000 gal, Hayward 220t sand filter, vinyl liner, dolphin m4 supreme.
    If TFP has helped you, please click to SUPPORT TFP!
    Helpful Links:
    GET A TEST KIT Chlorine/CYA Chart How to SLAM About Metals & Stains

  7. Back To Top    #7

    Join Date
    Aug 2016
    Location
    Houston/Texas
    Posts
    6

    Re: First TF-100 Test - What to do next?

    Sorry for the delayed reply, still moving boxes from our previous house My water is clear and I do not believe I have algae. I had read that I should SLAM the pool to start, but it was a cursory read so I probably didn't get enough context. Interestingly enough, in a few of the areas that disappeared with a Vitamin C pill, the stain is back? Could this indicate that rebar is close to the surface of the plaster? Is there any 'cure' for that?

    I have maintained my FC using the Poolmath calculator for a CYA of 90 using 10% bleach. It feels like a lot of Chlorine and therefore I was thinking about doing another water change so that I don't nuke my kids during the rest of the Texas summer (Until November).

    Water source is city of Houston water, not a well.
    Screen Shot 2016-08-16 at 8.36.36 AM.jpg

    Water report is above. Note that they don't provide iron content in the water. Interesting that there are Chloramines. Also, glad that Uranium is not present - that would be a bummer, although I am sure it would solve any algae problems

    I went to the pool store and they tested for metals. Not sure how accurate it is though - Iron was at 0.8 ppm, no copper detected. My guess is that the metals are coming from the city water.

    So - assuming I do an OCLT and I am OK then shall I lower the CL and dump some ascorbic acid in with a sequestrant? I saw a product called C U Lator on youtube. Looks like an easy way to remove the metals from suspension. Any thoughts?

    Thanks so much for all the help. Nice to be able to do this right.
    17,000 gallon gunite pool, Pentair FNSP60 DE filter, Century Centurion 2.6HP main, 0.75 HP Polaris PB4-60 Booster, Polaris 280

  8. Back To Top    #8

    Join Date
    Aug 2016
    Location
    Houston/Texas
    Posts
    6

    Re: First TF-100 Test - What to do next?

    Pic of staining at deep end of pool - note that we just had a few thunderstorms so there is some debris there awaiting pickup by the 280...

    IMG_1672.jpg
    17,000 gallon gunite pool, Pentair FNSP60 DE filter, Century Centurion 2.6HP main, 0.75 HP Polaris PB4-60 Booster, Polaris 280

  9. Back To Top    #9
    needsajet's Avatar
    Join Date
    Jan 2016
    Location
    Sydney, NSW, Australia
    Posts
    3,552

    Re: First TF-100 Test - What to do next?

    I'll leave the metals treatment to our expert, Swampwoman.

    Chlorine is measured in pools as free chlorine (FC). This measurement includes the chlorine that is bound in an inactive form with the CYA, so you can rest assured that no level we recommend is harmful to you or your family. One of the principles of TFPC is to keep the pool entirely safe all the time. The CYA binds the vast majority of the free chlorine, leaving only a small amount of active chlorine which is the part that does the sanitizing.

    A lower CYA level just makes the pool easier to SLAM. It sounds like you don't need to SLAM, but bringing the CYA down will make the pool a bit easier to manage, and is a good opportunity to remove some iron.
    12k IG salt; glass beads in plaster; K-2006C, K-1766, CCL, and Aussie 4in1 (HTH); Pentair Eco800 1.2HP VS; Zodiac SWC 1.3 lb/day (25 g/hr); 25" filter recycled glass; OKU solar panels; 1/2 HP solar pump; Rebel (Warrior) pool cleaner; FlowViz; prior pool AG 10k | Read Before Posting to get the best possible advice | ... and this helped me a lot!: TFPC for Beginners

  10. Back To Top    #10
    Swampwoman's Avatar
    Join Date
    Apr 2012
    Location
    Grand Rapids, MI
    Posts
    3,534

    Re: First TF-100 Test - What to do next?

    I went to the pool store and they tested for metals. Not sure how accurate it is though - Iron was at 0.8 ppm, no copper detected. My guess is that the metals are coming from the city water.
    Good morning, Texas. Metal measurement is actually one test the pool store can be decent at

    .8 ppm is pretty high...sure fire staining is at .3 ppm. If your municipal water doesn't stain your sink, my guess is that the source water isn't as high but that over time it has accumulated in your pool.

    SO, I really like max2k's idea about doing the ascorbic acid treatment then partial drains to get both your cya AND your iron concentration down, but here are my reservations/caveats for a new pool owner on that front:

    1. The AA treatment and low FC environment often has folks turn green from algae because they take too long coming back from the treatment. If you end up having to slam, that burns off the sequestrant too (waste of money) and can lead to restaining.

    SO what you need to know here is that when you use AA, it WILL fight your chlorine when you try to raise it...often zeroing it out. The trick is to add FC, test in an hour, add FC, test in an hour, until you have broken down your leftover AA and have your TARGET FC from the FC/CYA Chart chart maintaining. But do this in a singe day...not over a few.

    2. In this case, you will not want to add the sequestrant (use Metal Magic or Jacks Magic for sure fire results) until AFTER you've refilled the pool -- it will need the lower concentration of iron to last/work well.

    So in this case, you would refill, add the sequestrant while the FC is still low and ph is in range (in this case, Jacks wants it at 7.2 but Metal Magic would want it at 7.6 ph. So if your tap water is closer to one or the other, that might guide your choice. But since you're to be adjusting your ph to 7.2 and maintaining low h per AA treatment instructions, Ack's is more consistent with your target parameters)

    BUT then still add your FC right away...test in an hour...add again etc. ignore any commentary re javks or metal magic about keeping FC low. It will still work (I've done this) in higher FC...its just slamming that wears it down.

    3. Lastly, using sequestrant will sometimes make your water look cloudy for a day or two while filter catches up with any excess calcium that as bound to the sequestrant.

    I fear this might obscure an algae breakout if one were to start. But if you treat then bring back and maintain FC right away the way I described, then you'd likely be confident enough to ignore any clouding and not slam with metals, one does everything in ones power to avoid the slam

    SO with those caveats, its a good plan of action. A bit fussy for a brand new pool owner, but if you're up for it, we'll guide you through. Here's the link on AA treatment in case you hadn't read (but sounds like you did) Ascorbic Treatment to rid Pool of metal stains

    And alternate approach would after-dilution to do the Metal Magic Sponge test ( http://www.proteampoolcare.com/image...SpongeTest.pdf )
    and see if that alone removes the stain. I had great success with ths aproach one year and never did another AA treatment again thereafter. In this case you are skipping AA and just adding a larger dose of sequestrant. It worked pretty well on my old vinyl pool and was easier to perform.

    I always found the AA test a bit nerve-wracking in terms of getting FC up to target without either overdosing or under dosing, each with unintended consequences

    Just so you know, going forward, you will need to add maintenance doses of sequestrant to keep the remaining iron in solution.

    Since you asked, I did not really have any luck with culator, but am on well and had a constant high source of iron at the time (2 ppm). I now use softened water to top up (its plumbed to my pool spigot) but as of yesterday, also have new water I'd trucked in for a liner change...so I get a fresh start with 24,000 gallons of metal free water

    Once you've digested this and formed your plan of action, let us know and please feel free to ask any questions!
    In ground extended Grecian, 22,000 gal, Hayward 220t sand filter, vinyl liner, dolphin m4 supreme.
    If TFP has helped you, please click to SUPPORT TFP!
    Helpful Links:
    GET A TEST KIT Chlorine/CYA Chart How to SLAM About Metals & Stains

Posting Permissions

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