Pool Stains - unsure what kind and best way to proceed

[tmcdonald]

About 5 years ago I purchased a foreclosure home that had a pool. I knew (still don't know much) about pools and have been battling with this thing for years. I learned enough to clean up the swamp after moving in and have been able to get it balanced for summer usage, but it's still been a major drain on resources fighting to keep algae out etc.

All that to say, the previous owner did not take good care of it and there are now some sort of stains that have made the pool look, well, terrible, even when it's clean.

I'm wondering if this is black algae, or my plaster is just totally shot (it's old gunite/plaster from the 70's) or a mix of both? I've emailed pictures to poolforum@gmail.com since I don't have a great way of uploading.

Essentially, I want to know if there's anyway to get this thing looking sharp short of draining it and having the plaster totally re-worked (I've read estimates from people saying average cost is 12-25k for that...yikes)

Thanks for any advice/help!

[PoolDoc]

[PoolDoc]

Your pictures are not sufficiently high-resolution to be sure, but the top picture looks like copper stains that have been oxidized with high chlorine; the bottom picture looks like dirt.

Put a Vitamin C tab on the area in the top picture, and see if it affects the stain: if it does, it's probably a copper stain.

Brush the bottom area, and see if there is any effect. Dirt will move. Brown-orange stains are usually iron; brown-brown stains are usually organic.

[tmcdonald]

Thanks for the information - I'll check into those options. I passed along some pictures that should be higher-res, but after looking at them again, it's very hard to really tell what the bottom of the pool looks like :/ - I'll have to try again when it's more cleaned up for summer and there's some better light I think.

Essentially, I've got that nasty pool step, a ring around the entire bottom of the pool that looks similar, and that look like various patches and lightening bolt-esque stains across the bottom of all sorts of colors. Generally though they are dark like the others.

If most of these stains have been caused by copper (perhaps from use of copper algaecide?) - is there any way to get these out of the pool?

Finally, the bottom picture isn't dirt...scrub it and nothing happens. I've got spots and lines similar to that all across the bottom in various shades.

[PoolDoc]

I got your pictures, as you noted, they really don't reveal much.

Go ahead and try the Vitamin C on both the steps and the other area. But, it may be necessary to clean up the water, in order to get clear picture (accidental pun! ) of what's happening.

Copper typically comes from added chemicals (algaecides, 'mineral' devices or chemicals), or from corroding pool heaters. Rarely, it's present in fill water. Have you been using copper algaecides a lot?

Assuming the black stains are copper, it may not be possible to remove them completely without acid washing your pool. But acid washing is sort of a devil's bargain: nice white pool now, but at the cost of a rougher surface that is even MORE susceptible to stains.

If you're not going to go with an acid wash, you should do the following:

1. Get a local OTO / phenol red testkit. Use it to keep the chlorine between 1 - 2 ppm. Gradually lower the pH to 7.0 - 7.2. Make sure your pump is on 24/7. Also, report on Vitamin C results ASAP.

2. Order all of the following: K2006 test kit (Taylor K2006A (3/4 oz bottles) or Taylor K2006C (2 oz bottles) @ Amazon, and at least 2 quarts of polyquat (Kem-Tek 60% polyquat @ Amazon) and 2 quarts of HEDP (Kem-Tek 338-6 Metal & Calcium Eliminator Pool and Spa Chemicals, 1 Quart @ Amazon). I can't really advise on exact quantities, without knowing your pool's size.

3. Report K2006 test results as soon as you can. CYA levels are very important to know, and CYA testing with test strips is horrendously inaccurate.

4. Follow label dose recommendations on the polyquat & HEDP.

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The goal is to get the pool water into condition to lift the copper off the plaster. Lowered pH is part of this; avoiding high chlorine is another part, and the HEDP is yet another bit. Using the polyquat, which is BOTH an algaecide and a clarifier, will help you clean up the water, while maintaining low levels of chlorine. Since high chlorine tends to cause copper to drop out and stain surfaces, this is important. Also, no matter what the stains are, the polyquat + HEDP will not make it worse.

Check into what it costs to drain and refill. It may be possible to get the copper off the plaster, and back into the water, but it's tricky to get the copper out of the water and onto the filter -- but NOT the plaster. With as much copper as you appear to have, it may be best to chemically dissolve the copper, and the drain and refill the pool.

Do report on the Vitamin C results. It's unlikely the HEDP will 'lift' all the copper, but if Vitamin C will, we can help you buy bulk ascorbic acid, and use it. It's NOT chlorine compatible, so you have to follow a careful process to lift the stains without having your pool turn green while there's no chlorine present.

Good luck!

[tmcdonald]

Thanks for your help and info. I've been sidetracked with work, life, etc. and am just now trying to get my attention back on the pool.

1) I have been using a lot of copper algaecide over the last few years to combat serious algae problems..this is what the pool store told me to do. However, these stains were present BEFORE I started using these chemicals - although they may have gotten worse I'm not sure.

2) If I follow the steps you mentioned and purchase all of those products, can I get the pool balanced and keep any eliminate any existing algae without the use of copper algaecide? I don't have a good test kit and have never really gotten the pool balanced well, nor do I know the process without using algaecide. I'll look into what you suggested.

3) My pool is ~ 25,000 gallons I believe.

At this point I'm thinking that trying to remove the stains will have to wait until next spring. I just want to get the water balanced so that I can enjoy the pool and not have to dump a ton of money into algaecide and other products. I already need to replace my filter sand .

[PoolDoc]

Hi TMC;

1. It's probably a good idea to run without messing with the stains this year. I can actually show you how to do so, in a manner that will probably gradually reduce the stains. As you say, focus on just basic operations this year.

2. It's absolutely possible to run algae free without algaecide. Virtually the only time experienced PF users use algicide is for special purposes, for example when they'll be gone for a week. There *do* seem to be a few pools that have recurrent mustard algae, for reasons I haven't been able to discover. However, it appears -- in these limited cases -- that running low phosphate levels will resolve that problem. But generally, we don't recommend phosphate removers.

3. The starting place of getting control of your pool is accurate testing, and the K2006 is the best tool for that. We *still* haven't heard of that kit being sold locally; I know that the wholesaler in Chattanooga has never stocked any of them!

[tmcdonald]

Awesome thank you!

I'll grab that test kit and we can go from there.

Thanks again for your help - should I post some numbers after I get the test kit?

-Todd

[tmcdonald]

Back to the pool...

Finally got around to ordering and have now received the test kit. I have to admit, it's made me feel stupid, but I think I've mostly got it figured after finally sitting down for a few minutes to read.

One question - my chlorine test says 1 drop =.2ppm, us 25ml sample. for 1 drop = .5 ppm, us 10ml sample.

On the front of the testing box it says 1 drop = .2 or .5ppm chlorine...I'm not sure how big of a sample I need to use here .

Once I get that figured I think I can stumble my way through the rest.

Thanks again for your help,
-Todd

[PoolDoc]

Re: testing - use the 10ml / 0.5 ppm sample. That's more accuracy than you are likely to ever need. I can't even think of an occasion where it would have been nice to know chlorine levels to the nearest 0.2 ppm.