Stains

[jmerle]

I have used BBB from time to time and planned to this season. However, immediately upon opening the pool this HOT summer in NC, I encountered something that had never appeared in the 28 years since the pool was installed - mustard algae. I used algae 60 to no avail and the algae quickly spread over all the walls. It was disgusting.
Since most of the info I was reading indicated a copper based algaecide was necessaary to combat mustard, I used one containing 3% copper.The algae disappeared but a stain took its place over a large portion of the vinyl liner bottom. Assuming it was due to the copper, I tried an ascorbic acid product with no results. With ladies from the church coming for a pool party with my wife in a few days, I frantically gave the pool a super shocking. To my great suprise, the stain gradually disappeared over a day's time. Hoping to keep the algae away , I added No More Problems. The algae is still away, but I now have copper and bromide in the pool and cannot get a chlorine (or bromine) reading even after heavy shocking. The stains always return in 2-3 days.
Anything I can do? I wish I had paid better attention in chemistry class.
Data: 25K gal. vinyl liner: pH 7.4; CYA 25; TA 120

[PoolDoc]

More later, but quickly:

1. Keep your pH low.
2. Order polyquat, HEDP, and a Culator pack (links below).
3. Make SURE you have a good test kit -- you MUST have one.
4. Complete the pool chart:

Pool Chart Entry Form

I'll explain how and why this evening.

Ben

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+ Get a cheap OTO (yellow drops) / phenol test kit, or if available at YOUR Walmart (check availability), get the HTH 6-way DROPS test kit, which is compatible with the Taylor K2006. Test the pool as soon and you can, and post the results. If you get the 6-way kit, ALSO test the water you FILL the pool with, especially if it's a well, and post THOSE results as well. (The HTH is the best available kit you're likely to find locally, but it's not the K-2006. It can only provide rough measurements chlorine levels above 5 ppm, and it measures "TOTAL" hardness, rather than "CALCIUM" hardness, which is not ideal.)

+ Having a good test kit makes pool care easier for EVERYONE, but is an ESSENTIAL tool for pools with problems. A good test kit means a kit that can test chlorine from 0 - 25 ppm, pH, alkalinity, calcium hardness, and stabilizer with reasonable accuracy. Test strips (AKA 'guess-strips' ) do NOT meet this standard. Some pool store testing is accurate; most is not. The ONLY way you'll know whether your pool store is accurate or bogus, is by testing accurately your own self. On the other hand, pool store 'computer' dosing recommendations are NEVER trustworthy -- ignore them. They are designed to sell more chemicals than you need, and WILL cause many pool problems.

+ We recommend the Taylor K-2006 test kit, which meets the requirements above, for many reasons. The HTH 6-way drops kit is a great starter kit, and is compatible with the K2006 (it's made by Taylor). There are a few alternatives; for example Lamotte makes an FAS-DPD kit that's OK -- but it costs 3x as much. But, we're not aware of any test that is better, and since we are all familiar with the K-2006 (and can help you with it) we recommend it exclusively ( Test kit info page )

One caution for the 2012 season: Amazon does not stock the kits directly. So when buying at Amazon, Amato is our current preferred seller. However, they often don't list enough stock to last the whole day, so try order mid-morning. You should expect a delivered cost under $60 for the K2006A and under $95 for the K2006C. If you can't find that, wait a day.

+ Here are links to the kits we recommend (you can check local availability on the HTH kit, using the Walmart link):

HTH 6-Way Test Kit @ Walmart
Taylor K2006A (3/4 oz bottles) @ Amazon
Taylor K2006C (2 oz bottles) @ Amazon

HEDP is a dissolved phosphonate product that is pretty chlorine stable, and very good at keeping dissolved metals IN the water, instead of ON your pool surfaces. It can lift recent stains, OR it can be used along with ascorbic acid, to keep the metals in the water, after the ascorbic acid is consumed by chlorine.

Jacks Magic The Pink Stuff 1qt (60% HEDP) @ Amazon
20% KemTek HEDP @ Amazon

Using polyquat during metal clean up accomplishes two things: it helps kill or prevent algae, letting you run lower chlorine levels, and it is a very good clarifier, that helps you filter out any small metal particles that may form.(Probably available from pool stores, and possibly some big box stores -- but you MUST learn to ID it correctly. See the polyquat page for more info.)

Kem-Tek 60% polyquat @ Amazon
Nava 60% polyquat @ Amazon

Ascorbic acid (Vitamin C) can be used to remove copper and iron stains from pool surfaces, and put the metal BACK into your pool water. (Not likely to be available locally, except as Vitamin pills.)

Ascorbic Acid Powder @ Amazon
Ascorbic Acid Vitamin C Powder USP Pharma Grade 11 Lbs @ Amazon

The CuLator product is a special patented plastic material, contained in a bag that goes into the skimmer, that can slowly take metals OUT of your pool water. We think it works, and have some evidence that it does, but not proof yet. (Not likely to be available locally.)

1 ppm Culator @ Amazon
1.5 ppm Culator sold by Amazon, shipped from Periodic
4 ppm Culator sold by Amazon, shipped from Periodic
Poolmaster 16242 Poolmaster Skimmer Basket Liner @ Amazon (to protect CuLator from being damaged by scum)