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Thread: I've got lumps! (well, OK, my plaster has lumps, not me)

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    I've got lumps! (well, OK, my plaster has lumps, not me)

    Calling all ye' pool gods, I'm stumped after searching the interwebs.

    I've got what appear to me as calcium deposits all over the bottom of my pool. Most of the plaster is pretty clean, but I have these things. (Sorry, the picture isn't good, I'll try and toss the go pro in this weekend and get better ones.) I have small calcium deposits on the walls also, sort of look like stalagtites (stalgamites? I don't remember which ones grow up and which down )

    If I scrape them with a putty knife, they do break off, and leave the gray stain. At least I can get the lumps off.

    I'm wondering should I do a drain, scrape and acid wash? My other option is borrowing some diving tanks and scraping them down by hand. I'm just not sure what they are.

    Now,I'm in Phoenix - our water is about as hard as a pumice stone coming out of the faucet (hence assuming they are calcium?) - The water is crystal clear, with FC, Cholorine and acid levels normal (aside from the leaves, I had the robot cleaning up after the last storm.)

    I'm open to any and all opinions. I just have no clue....



    28K Gallon old-skool plaster hole in the back yard in desperate need of an acid wash and a fixed skimmer diverter (yes, it's still broken)
    Hayward SuperPumpVS pushing some giant hayward cartridge filter setup
    SharcVacXL and Zodiac G2 to keep things clean

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    Re: I've got lumps! (well, OK, my plaster has lumps, not me)

    Oh, and the lumps have chalky white stuff in them, and are gray - I don't think there is any metal contamination, so, think positive that the chemistry got all out of whack and the calcium spiked? Is there something I should be adding to take the calcium level down?
    28K Gallon old-skool plaster hole in the back yard in desperate need of an acid wash and a fixed skimmer diverter (yes, it's still broken)
    Hayward SuperPumpVS pushing some giant hayward cartridge filter setup
    SharcVacXL and Zodiac G2 to keep things clean

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    Re: I've got lumps! (well, OK, my plaster has lumps, not me)

    I would suspect that they are calcium nodules. What are all of your chemistry readings?

    Has the pool ever been painted?

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    Re: I've got lumps! (well, OK, my plaster has lumps, not me)

    James - Ok we're aiming the same direction. I need to pick up a "good" kit and get some real numbers (I'm only testing basic cholorine and acid levels) Maybe this is something I can ask the folks at the local (unnamed) shop test for?) They aren't great, but they test for free and it's a 2 minute walk from the house

    Is there something I should be looking for in the chemistry to prevent this? An "Anti-Calcium" formula of some sort? Aside from filling the pool via a water softener, I'm clueless!

    As for painted,no. Well, at least not that I can tell, it looks like plain old plaster to me.
    28K Gallon old-skool plaster hole in the back yard in desperate need of an acid wash and a fixed skimmer diverter (yes, it's still broken)
    Hayward SuperPumpVS pushing some giant hayward cartridge filter setup
    SharcVacXL and Zodiac G2 to keep things clean

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    Re: I've got lumps! (well, OK, my plaster has lumps, not me)

    would a draining and acid wash clear these up? I don't mind spending the $50 to drain and refill it on top of the cost of acid. I just don't want it to be in vain.
    28K Gallon old-skool plaster hole in the back yard in desperate need of an acid wash and a fixed skimmer diverter (yes, it's still broken)
    Hayward SuperPumpVS pushing some giant hayward cartridge filter setup
    SharcVacXL and Zodiac G2 to keep things clean

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    Re: I've got lumps! (well, OK, my plaster has lumps, not me)

    Use that $50. get a good test kit!
    26' X 52" Intex Ultra Frame. Intex Sand Filter
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    You can lead a horse to (clear) water, but you can't force him to swim in it!

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    Re: I've got lumps! (well, OK, my plaster has lumps, not me)

    http://www.poolhelp.com/handouts/oB_...%20Handout.pdf

    Calcium Nodules Part I - YouTube

    See the above references.

    You really need to get a good test kit so that we can figure out what the issues are.

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    Mod Squad kimkats's Avatar
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    Re: I've got lumps! (well, OK, my plaster has lumps, not me)

    Brett a good test kit will be your saving grace with your pretty pool. Look in my siggy and order that one please.

    I guess you could take your water to the PS BUT I would NOT buy anything they say! That could hurt more than it helps. Wait for YOUR test results with YOUR test kit before you do anything.

    Kim
    TFP Moderator 33x52 round AG 25,600 gals Sand Filter 1.5hp Pump - 2 Speed, SLAM, Pool School, Recommended Levels, Recommended Chemicals, Pool Math, Chlorine/CYA Chart, TF-100 Test Kit

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    Re: I've got lumps! (well, OK, my plaster has lumps, not me)

    The spots look like they could be paint bubbles that have popped or maybe fiberglass bubbles if the pool has been painted or resurfaced with fiberglass. Can you confirm that the surface is regular plaster?

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    Re: I've got lumps! (well, OK, my plaster has lumps, not me)

    James - the finish is regular plaster. Definitely NOT paint. After spending a bunch of time on the OnBalance site, they are definitely calcium nodules, so, even balancing the water won't get rid of them or prevent them. (Like I mentioned, our water is really hard here, and apparently this is not an uncommon thing.)

    What I still can't figure out is the best way to clean them off. Right now I'm looking at either using some scuba gear and scraping while the pool is full, or draining and acid washing, where I can scrape them in the dry. (I'm not really against draining and acid washing or TSP bath, since it would give me a chance to fix the darn light once and for all, and the rest of the bottom is a little dingy looking)

    It's starting to warm up (86 here today!) so Ill try and toss the camera in and get some underwater pictures.
    28K Gallon old-skool plaster hole in the back yard in desperate need of an acid wash and a fixed skimmer diverter (yes, it's still broken)
    Hayward SuperPumpVS pushing some giant hayward cartridge filter setup
    SharcVacXL and Zodiac G2 to keep things clean

  11. Back To Top    #11

    Re: I've got lumps! (well, OK, my plaster has lumps, not me)

    Draining can be risky. High ground water can float the pool. Also, your plaster is getting voids, which can become large areas of delamination when exposed to heating and cooling while drained.

    It would be better not to drain. However, you might not be able to get a satisfactory result without draining. You might need a full replaster.

    Getting an expert opinion from someone who can visit the pool would be best.

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    Re: I've got lumps! (well, OK, my plaster has lumps, not me)

    Yeah I think I'm going to nix the draining. Guessing that's what may have caused this in the first place. (Although, not worried about float, our water table is about 400 feet down, and we are requested by the city to drain directly to our sewer clean outs.) After all of the reading, acid washing doesn't appear to help anyway.

    When the water is a tad bit warmer, I'll do some scraping. I had a little luck scraping them last year. I wouldn't be surprised if the lagoon needs a full plaster job, given I have no idea how old the plaster actually is. Best guess is it's going on AT LEAST 15 years. No one else seems to notice them, but I do, and it drives me nuts!
    28K Gallon old-skool plaster hole in the back yard in desperate need of an acid wash and a fixed skimmer diverter (yes, it's still broken)
    Hayward SuperPumpVS pushing some giant hayward cartridge filter setup
    SharcVacXL and Zodiac G2 to keep things clean

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    Mod Squad pooldv's Avatar
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    Re: I've got lumps! (well, OK, my plaster has lumps, not me)

    It is possible to avoid calcium scaling with hard water. There are people on TFP who manage water with CH of 800 ppm and higher. Use Poolmath to manage your CSI.

    More here
    Pool School - Calcium Scaling

    and here
    Langelier and Calcite Saturation Indices (LSI and CSI)
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