Rust Spots?

Total hardness and calcium hardness in pool water.
Scale, calcium buildup, hard water and scaling problems.
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Rust Spots?

Postby dj000524 » Fri 08 Aug, 2008 15:39

Bought my house 3 weeks ago with a inground gunite pool. Everything had seem to be going ok until the other day when I noticed what looks like rust spots on the bottom of the pool. It is in both the shallow and deep end. I have tried scrubbing with a brush but these spots didnt come up. Can someone help with what might be done to remove these spots. Do I let it go until winter drain the pool and put a fresh coat of paint and sealer on it? Any help would be great!
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Rust Spots?

Postby muss08 » Sat 09 Aug, 2008 07:49

Rust spots are very nasty and difficult to get rid of. First, get your water tested for iron, lower the pH to 7.2-7.4 and add a metal sequesterant. Depending on how deep the stain is it may or may not get rid of the stain or lighten it. The sequesterant will also help to prevent any other stains if there is iron in the pool. If there is not iron in the pool then a piece of rebar under the surface could be rusting and the rust is seeping through the surface. IF this is the case it will be necessary to cut out that piece of rebar but this is usually a last resort. Are you sure the pool is painted and not plaster? If it is plaster you can acid wash that particular spot with a stain master which will remove the stain as well.
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Rust Spots?

Postby ka » Tue 11 Aug, 2009 23:43

I had the same problem and found out it wasnt anything in the water but was metals from the pool heater as my heater had not been used in was begining to corrode on the inside and when the heater and pump ran together it flushed out little paricles of rust in my pool. Still have not figured out how to remove these spots.
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Rust Spots?

Postby Aquaclear-NZ » Tue 01 Sep, 2009 03:04

Sounds just like rust - was anyone using a grinder on steel shortly before you brought the house near the pool ? have seen that more times than i care to remember.

Citric acid based treatments are best, can be purchased in bulk through bin-inn style places, or packaged as citra clean from lo-chlor chemicals

once the stain has been lifted from the surface with this method (will be easy if they are quite fresh) then you should use a sequestreant as recommended above
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Rust Spots?

Postby czechmate » Tue 01 Sep, 2009 11:36

Iron from fertilizer, worm pup, chunk of trichlor directly on the plaster and of course the iron content in the fill water will cause brown spots. Organic stain will be taken care of by chlorine. Others by "Pool stain remover" which is the best on the market. You may try to use a steel brush if you need to.

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