Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 7 of 7

Thread: does anyone know what this stuff is and how to remove it

  1. Back To Top    #1

    Join Date
    Dec 2012
    Location
    Tampa, FL
    Posts
    6

    does anyone know what this stuff is and how to remove it

    Newcomer to the forum here.

    Does anyone have a clue what this substance is on my pools walls? It's green, hard, and gritty and seems to be imbedded into the plaster. I have tried scrubbing it off with a steel brush to no avail. Since the attached picture was taken, I have added water (low level in picture), shocked, brushed, vacuumed, cleaned filter until the water is clear with no new algae forming. This stuff refuses to come off no matter how much I scrub.

    21,000 gal, IG Concrete w/ raised Spa, Hayward Star-Clear Plus 120 SF Cartridge Filter, Hayward H250 LP Spa Heater
    1.5 hp Marathon Pump Motor

  2. Back To Top    #2
    bobodaclown's Avatar
    Join Date
    Apr 2011
    Location
    Lakeland, FL
    Posts
    2,351

    Re: does anyone know what this stuff is and how to remove it

    Rub a trichor puck against it. If it lightens you might be able to use that to get rid of it. If not then try a vitamin C tablet against it. If it lighten then its metal staining.

    What's the surface of the pool?

    Others will chime in with time.

    I hope its not black algae. It takes longer to go away.

    Also Mr. Clean Magic Eraser may work on the tile or an acid wash if its calcium staining.
    17K Kidney Shaped Pool Concrete (Diamond Bright) Pool, 3/4 hp 2 speed 115V Sta-rite Duraglas PEA5D-180L/P2R5D-181L (Impeller C105-92PS Diffuser C1-216P), 1.5 piping, Pentair CC100 Filter , Heat Siphon 100K BTU Heat Pump Pool Heater, Flow meter Blue White Flowmeter Model No. F-30150P, Hayward Astrolight SP0581N, SWCG CalimarTitanium Edition TE45 , Dolphin Nautilus Plus with CleverClean, Lakeland Florida

  3. Back To Top    #3

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,085

    Re: does anyone know what this stuff is and how to remove it

    Well, I have to guess on this one so take it for what it's worth......

    Your description and it's appearance make me think it is a combination of calcium scale and algae. The calcium scale comes from pH too high over a pretty long period and, algae can accumulate and grow in it. The result is VERY hard to kill algae because it can "hide" in the scale and, like you said the scale alone is quite difficult to remove.

    I think you are going to have to lower the water line and treat the scale directly with a good dose of muriatic acid and then shock your pool to get rid of the conditions that have encouraged the algae to grow.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  4. Back To Top    #4

    Re: does anyone know what this stuff is and how to remove it

    In the picture it looks brown above the waterline which would indicate iron, dead algea or tannic acid stains. The tile also appears to have a good bit of scale. If you have a heater it could be copper. I think duraleigh got it right.

  5. Back To Top    #5
    y_not's Avatar
    Join Date
    Jul 2012
    Location
    Redmond, OR
    Posts
    1,086

    Re: does anyone know what this stuff is and how to remove it

    BTW, this is what we mean by "shocking" your pool.
    pool-school/defeating_algae

    It's a process, not a product you dump in and call it "shocked".
    Read the 1st link at the end of the article as well. You will need a FAS-DPD chlorine drop test kit to perform this procedure, they are discussed here.
    pool-school/pool_test_kit_comparison
    Thanks for reading... - Tony
    Da' Pool: Intex 15'x42" 3284gal AGP EasySet (Inflatable Ring) - (Summer 2014: 27' round EW /w 6.5' deep end @ 22,500gal)
    Pump & Cart Mod: 1000gph Cart. 5ft² - 2 nylons, 24/7 OP. Traps bugs/bits, lasts longer/cleans easier = Happier Pool Owner!!
    The Bible for a "Trouble Free Pool" life = PoolSchool, the BBB method a TF100 test kit(Recommend Kits Compared). - Cleaning a Sand Filter
    Water looks like GLASS, if yours doesn't...SLAM IT! Feels nice and never been happier!!! :D

  6. Back To Top    #6

    Join Date
    Dec 2012
    Location
    Tampa, FL
    Posts
    6

    Re: does anyone know what this stuff is and how to remove it

    Thanks for the info so far.

    Here are the numbers...

    FC = 38
    CC = 0
    TA = 90
    CH = 370
    CYA= 60
    pH = 7.5

    I have been holding the FC above shock level for my CYA and it's not going away. It must be a dead algae/calcium scale mixture as duraleigh suggested. I will probably have to drain and treat directly.
    21,000 gal, IG Concrete w/ raised Spa, Hayward Star-Clear Plus 120 SF Cartridge Filter, Hayward H250 LP Spa Heater
    1.5 hp Marathon Pump Motor

  7. Back To Top    #7
    y_not's Avatar
    Join Date
    Jul 2012
    Location
    Redmond, OR
    Posts
    1,086

    Re: does anyone know what this stuff is and how to remove it

    Are you brushing it regularly while at shock level?

    As for draining, an alternative would be to keep your water on the negative end of the ceiling index. With regular brushing it'll go away.
    Thanks for reading... - Tony
    Da' Pool: Intex 15'x42" 3284gal AGP EasySet (Inflatable Ring) - (Summer 2014: 27' round EW /w 6.5' deep end @ 22,500gal)
    Pump & Cart Mod: 1000gph Cart. 5ft² - 2 nylons, 24/7 OP. Traps bugs/bits, lasts longer/cleans easier = Happier Pool Owner!!
    The Bible for a "Trouble Free Pool" life = PoolSchool, the BBB method a TF100 test kit(Recommend Kits Compared). - Cleaning a Sand Filter
    Water looks like GLASS, if yours doesn't...SLAM IT! Feels nice and never been happier!!! :D

Posting Permissions

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