Ascorbic acid treatment and SLAM for algae and metal stain issues

[boston2austin]

Hello,
I have had a fairly large stain on the bottom of my pool for several years. I have always suspected that it was iron and have used the vitamin C tablet test a couple of times. It never gets bigger or brushes of, but it is somewhat unsightly and I am ready to get rid of it. I do not believe the source of the metal stain to be the water, but a small piece of rebar that is exposed on the decking. When it rains heavily, I think that this spills water into the pool. (covering that will be on my agenda, too) A few weeks ago, I did a larger scale Vit C tablet test and it made a big difference. The sock, as I rolled it over a few hours left a large clean area. I just don't think sock fulls of Vitmin C filled socks will be efficient. Ha. I looked around at the Ascorbic acid water treatment and sequestration, and I think I would like to try. I was really thinking a one time treatment, not ongoing.

However, after getting through our pollen, leaves and oak tree shoots here in Austin throughout the early spring, I have determined I may have an algae problem. The pollen often looks like algae, making your water green and leaving deposits. the pollen is gone, the filters changed, the debris cleaned, and the pool brushed several times over. Yet, I keep coming up with removable stains on the sides, the seats and a bit in the corner of the stairs and around the jets. Thus I have concluded algae. It is greenish brownish yellowish. Therefore, I am thinking I may need to SLAM. So there are several questions i was hoping you might be able to help me with...

1. Can I do both, separately over the next few weeks?
2. Which to do first?
3.How long should I wait between?
4. Could I have the links to the full process for both treatments?
5. When will the sequestering agent and AA be dissipated? Are those agents safe, My dog does drink small bits from the pool?
6. would the 'Culator' be an effective sequestrant in this situation?
6. do you have any other suggestions?

Currently I am keeping the pool at 5-6ppm Chlorine with a pH goal of 7.5.
water test now = pH 7.8, CL 7, CC 0, CYA <20, TA 120, CH 300+

Thank you in advance!

 

[mknauss]

I have no experience with AA treatments so will give this thread a bump to see if someone can help out!

Take care.

 

[boston2austin]

Thank you

 

[aeh0603]

I did both on my pool shortly after I found this site. You are correct in your plan to do then separately too. The processes would fight each other and not really work if you tried to do them at the same time. To answer your question:

1. Yes
2. Depends... Are you planning to drain/exchange water to reduce the metal concentration in your water after performing the AA treatment? If not you should plan on an ongoing use of a metal sequester to prevent future staining. (My recommended order of SLAM and AA treatment depends on your anser)
3. This depends on the order of treatments so I'll answer after you answer my question in #2
4. I'm on my phone right now so it's not easy so send links. I'll try to sign in on my computer later to add links but both can be found in pool school on this site.
5. Not sure. My dog doesn't drink the water so I've never looked into this.
6. I've never used "culator" but I think that's one of the ones people use on this forum? Not sure here. I used pro team metal magic.

In my case, my pool was green when I found this forum a few months after buying my house. I was able to clear the green by adding bleach rather blindly while I waited for my test kit to arrive (so not a real SLAM). With my first test results I discovered my FC was sky high and my CYA was over 200! Since I knew I needed to drain/exchange a significant amount of water to get my CYA level in line. I decided to let my FC drop, used a polyquat 60 algecide to help lower the risk of algea while my FC was intentionally low, and did the AA treatment to remove significant staining throughout my pool. When I finished the AA treatment I then did I think 3 cycles draining about 50% of my pool and filling it back up to lower my CYA (and also lower the now sequestered metal from the AA treatment). At this point I had a small amount of algea again so I performed a SLAM (my first real SLAM) to make sure all the algae was dead and gone.

 

[aeh0603]

The sequesraunt is a recurring treatment that simply binds the iron in solution to keep it from precipitating out. The CUlater is advertised as polymer product that mechanical attempts to "grab" the iron particles. Nothing wrong with using them at the same time as far as I am aware of.

With backwashing and exposure to chlorine, you can expect sequestraunts to eventually weaken and require replenishment. Try to keep the pH controlled since a high level of pH aggravates iron - so does excessively high chlorine.

Also see: Stains in Your Pool - Trouble Free Pool

I just found this in another thread and it answers one of your questions too

 

[boston2austin]

thank you for your reply, A! I will not be doing a water exchange. Without a known, ongoing infiltration of metals, wouldn't one round of sequestrate be enough? My pH is always riding high, around 7.8, requiring weekly acid additions. Will bringing my TA back in line reduce that need. I have seen around that the high pH can aggravate the metal staining. Thanks, again.

 

[mknauss]

Sequestrate is an ongoing program. It is degraded by chlorine. So if you do metal sequestration, you must add the material on a regular basis. See the manufacturer of the product you will be using for dosage and how often.

 

[aeh0603]

If you don't want to drain water, then SLAM first, high chlorine levels can cause the metal in the water to oxidize and turn your water green (copper) it brown/rust (iron). High chlorine will also degrade your sequesterant faster.

After your SLAM, let your chlorine come down to normal levels then follow the AA treatment directions. You will need to continue a maintenance dose of sequesterant to ensure the metal stays suspended in your water and doesn't re-stain your pool.

 

[aeh0603]

I just wanted to add the other option since you also said you do not want an ongoing regimen of adding sequesterant. In this case you would do it more like I did. Assuming your pool is clear enough that you can see the staining on the walls and floor, then start with the AA treatment. You will still use one dose of sequesterant as part of this procedure, but when you complete the AA treatment you then either drain and refill it, or do a water exchange. Replacing water at this point will reduce the concentration of metals in your water so they won't re-stain your pool. If you are reasonably sure you have eliminated the source of metals, then there will be no need for regular doses of sequesterant. After the drain/refill or water exchange is complete you would then do your SLAM.

 

[boston2austin]

Thank you for your replies!