Pool Stains - unsure what kind and best way to proceed

[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.

[tmcdonald]

Here's my test info....as best as I could get

free chlorine: 2 drops x .5ppm = 1ppm by my calculations
combined chlorine: 1 drop x .5ppm = .5ppm
ph: 7.0 or below...close to 7 though by color
alk = 6 drops gave me a pink color..not red...11 drops in I was still pink so i stopped. that would give me 60ppm-110ppm...but again..never turned red.
calcium hardness: water turned pink/purple around 10 drops in...it was lighter purpler at 30 drops in..never turned blue and I stopped at 30 drops.
cyA: I got half way between the bottom and the first mark at 100 - no number was present.

Sorry things came out kind of funny..let me know if I need to adjust or if that gives you a good enough idea what I'm dealing with