Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 8 of 8

Thread: Yellow dirt/grime on bottom of the pool

  1. Back To Top    #1

    Join Date
    Jun 2016
    Location
    Kingwood, TX
    Posts
    7

    Yellow dirt/grime on bottom of the pool

    I purchased a home with an approx 15,000 gallon pool. It was dirty but clear when I made an offer but a month later it turned into a green swamp after massive rains. 2 weeks ago it was cleared up by the pool company but when I finally moved in it was very cloudy.

    My rest results showed very little of every chemical and was very cloudy and after following the guides here and the pool calculator I am happy the say the pool is very clear now.

    Current readings:

    FC - 2.8
    CC or TC - 3.1
    pH - 7.2
    TA - 75
    CH - 185 ( ordered some deicer from home depot, will come next week)
    CYA - currently at 92 but don't remember what it was before. - maybe 10?

    The problem I have now is yellow grime/dirt build up on the bottom of the pool. I am unable to scrub it off.

    Can you please recommend something? It's a bit hard to see in the pictures.

    http://imgur.com/a/FirTL

  2. Back To Top    #2
    Texas Splash's Avatar
    Join Date
    Jun 2014
    Location
    South-Central Texas, Marion/San Antonio
    Posts
    12,981

    Re: Yellow dirt/grime on bottom of the pool

    Hello and welcome to TFP! It's great you are seeing some improvement and feel better using the TFP methods. Let's confirm or go over a few things:
    - How are you testing (which test kit)?
    - If you are using a TFP-recommended test kit, then your reading tell me:
    1.FC is low and requires bleach to be added right away. How much depends on your CYA (next item)
    2. CYA - It was low and now high? How high? What did you add, how much, and when did you add it?

    So if your water is still clear, that's a good thing. But you must get the FC/CYA levels correct quickly to avoid going backwards to cloudy water and algae. Please respond to those two questions and we can help you more from there okay. Great to have you with us.

    - - - Updated - - -

    Also, please add your pool info to your signature by going to the top of the TFP web page (just under the Pool School button) and select "SETTINGS". On the next page look to the left for a menu bar that says, “MY SETTINGS” and go to "EDIT SIGNATURE" to enter your pool and equipment info there. It will help us later. This link may also help you: Pool School - Read This BEFORE You Post.
    Pat (a.k.a. Texas Splash) ~ My Pool: Viking Fiberglass; 17,888 Gal; Waterway Supreme 2-sp/2-hp pump; Hayward Ctg filter; TF-100 w/ Speed Stir
    Vital Links: POOL SCHOOL, RECOMMENDED LEVELS, RECOMMENDED CHEMICALS, Poolmath Calculator, SLAM, Chlorine/CYA CHART.
    If you enjoyed your TFP experience, please consider donating to Support TFP!

  3. Back To Top    #3

    Join Date
    Jun 2016
    Location
    Kingwood, TX
    Posts
    7

    Re: Yellow dirt/grime on bottom of the pool

    Updated original thread for CYA level - I am using the ColorQ test tubes.

  4. Back To Top    #4
    Texas Splash's Avatar
    Join Date
    Jun 2014
    Location
    South-Central Texas, Marion/San Antonio
    Posts
    12,981

    Re: Yellow dirt/grime on bottom of the pool

    Okay. Well, the COlorQ isn't one of the TFP-recommended test kits, but it's also not the worst out there. But I would be cautious because the most important variable in your situation right now is that CYA. If it is indeed over 90, that's just too high and what it does is places an almost unrealistic FC demand on your pool to compensate. Take a look at the Chlorine/CYA Chart link below in my sig. You can see how much FC you need on a regular day with a CYA of 90+, but then to increase to "SLAM" level to eliminate algae it's really high - safe for the pool but a lot of bleach. I have no idea what happened with your CYA dosage, but if I were you, I would reduce that CYA. I'll say this too just in case for your to consider ... but I would also order a TF-100 test kit. The testing in that TF-100 is generally more accurate and reliable. Your CYA could actually be higher or lower that what the ColorQ is showing. Just a thought. As for the yellow stains you mentioned cannot be scrubbed-off .... perhaps organic. We have a few methods to try when it comes to stains.
    Pat (a.k.a. Texas Splash) ~ My Pool: Viking Fiberglass; 17,888 Gal; Waterway Supreme 2-sp/2-hp pump; Hayward Ctg filter; TF-100 w/ Speed Stir
    Vital Links: POOL SCHOOL, RECOMMENDED LEVELS, RECOMMENDED CHEMICALS, Poolmath Calculator, SLAM, Chlorine/CYA CHART.
    If you enjoyed your TFP experience, please consider donating to Support TFP!

  5. Back To Top    #5

    Join Date
    Jun 2016
    Location
    Kingwood, TX
    Posts
    7

    Re: Yellow dirt/grime on bottom of the pool

    is it mustang algae?

  6. Back To Top    #6
    Texas Splash's Avatar
    Join Date
    Jun 2014
    Location
    South-Central Texas, Marion/San Antonio
    Posts
    12,981

    Re: Yellow dirt/grime on bottom of the pool

    Mustard algae is a yellow green color and usually grows on the walls and floor mostly on the shady side of the pool. I've not known it to be so difficult that it couldn't be scrubbed. Even if it was, the treatment for MA is the same as standard algae - a SLAM (first). Pass a regular SLAM then increase FC for 24 hours to "MA" level. Your biggest concern right now has to be that CYA and knowing for sure that the CYA reading you have is reliable. I've never used the ColorQ, I'm just going-off of the other threads here at TFP that commented on its prior use by other members.
    Pat (a.k.a. Texas Splash) ~ My Pool: Viking Fiberglass; 17,888 Gal; Waterway Supreme 2-sp/2-hp pump; Hayward Ctg filter; TF-100 w/ Speed Stir
    Vital Links: POOL SCHOOL, RECOMMENDED LEVELS, RECOMMENDED CHEMICALS, Poolmath Calculator, SLAM, Chlorine/CYA CHART.
    If you enjoyed your TFP experience, please consider donating to Support TFP!

  7. Back To Top    #7

    Join Date
    Jun 2016
    Location
    Kingwood, TX
    Posts
    7

    Re: Yellow dirt/grime on bottom of the pool

    It rained for 4 days straight and I re-tested after adding a bunch of chemicals last night and these are my levels.


    FC: 4.83
    PH: 7.6
    TA: 94
    CH: 147
    CYA: 25

  8. Back To Top    #8
    Texas Splash's Avatar
    Join Date
    Jun 2014
    Location
    South-Central Texas, Marion/San Antonio
    Posts
    12,981

    Re: Yellow dirt/grime on bottom of the pool

    On a normal day, if your water was crystal clear with no signs of algae, I might say those numbers are good with the exception the CYA which is slightly low (30 minimum). You haven't updated your profile/signature, but from the picture link you appear to have plaster pool, therefore your CH would appears to be a little low. You also didn't post your CC level which tells a little more about your water.

    At this point, based on your descriptions from post #1 and the pics, I would still recommend a "SLAM" as advised above in post #4. Since your CYA is low showing as 25 (round-up to 30), your SLAM FC level should be maintained at 12 and kept there until you pass the 3 SLAM criteria. In addition, I would still advise you to obtain a TF-100 test kit to accurately follow TFP recommended levels and instructions more accurately.

    Hope this helps.
    Pat (a.k.a. Texas Splash) ~ My Pool: Viking Fiberglass; 17,888 Gal; Waterway Supreme 2-sp/2-hp pump; Hayward Ctg filter; TF-100 w/ Speed Stir
    Vital Links: POOL SCHOOL, RECOMMENDED LEVELS, RECOMMENDED CHEMICALS, Poolmath Calculator, SLAM, Chlorine/CYA CHART.
    If you enjoyed your TFP experience, please consider donating to Support TFP!

Posting Permissions

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