Wow...this is a job for the experts

New couple just moved in across the street. Previous owners told them to keep the chlorine high. Popular pool store has been perpetuating the problems that have now led us here. I am a convert, former newbie who has had no pool problems since I found this forum. This one is out of my league, so here goes. I am using a Taylor K-2006 testing kit.

Vinyl pool (not positive but I think 18,000 gal)
ph: so low I couldn't measure it (30 drops of base demand made no dent)
alkalinity: Test was red from the beginning (I think because of the cya????)
cya: dot disappeared well before the 100 mark on my tester (high)
chlorine: 1.0
Located in Alabama, so water is cool but not freezing yet

My husband and I had a similar cya when we bought our house/pool and had to drain portions of the water in 3 cycles to lower our cya and calcium. I am leaning towards recommending the same, but I need help with the alkalinity/ph issues since I don't know what that alkalinity result means. I would also like to know your thoughts about the cya and whether to recommend that they consider draining some of the current pool water. My neighbors are going to join the forum as well and will be reading along. Thanks in advance. Man the pool stores stink.

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Originally Posted by bluecamel

New couple just moved in across the street. Previous owners told them to keep the chlorine high. Popular pool store has been perpetuating the problems that have now led us here. I am a convert, former newbie who has had no pool problems since I found this forum. This one is out of my league, so here goes. I am using a Taylor K-2006 testing kit.

Vinyl pool (not positive but I think 18,000 gal)
ph: so low I couldn't measure it (30 drops of base demand made no dent)
alkalinity: Test was red from the beginning (I think because of the cya????)
cya: dot disappeared well before the 100 mark on my tester (high)
chlorine: 1.0
Located in Alabama, so water is cool but not freezing yet

My husband and I had a similar cya when we bought our house/pool and had to drain portions of the water in 3 cycles to lower our cya and calcium. I am leaning towards recommending the same, but I need help with the alkalinity/ph issues since I don't know what that alkalinity result means. I would also like to know your thoughts about the cya and whether to recommend that they consider draining some of the current pool water. My neighbors are going to join the forum as well and will be reading along. Thanks in advance. Man the pool stores stink.

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(The pool stores stink because of all the chems they store there :) )
Seriously, I have seen the exact same thing on so many pools, it's not funny (unless you don't like the pool owner - in which case, it's a reason to raise a toast ;) ) From my experience with many pools with the same problem, they have used a tri-chlor feeder and not bothered to test (even weekly :eek: ) their pH and alk, this results in a very high cya and a very! low pH. When I see it, it's because the owners have dissolved the heat exchanger in their heater (acid likes to disolve metals, like copper), and we have to do a $1200 replacement. I also have seen the 'warning signs - the nut on the DE grids will be 'brick red' or 'teal green' when we clean the filter. If your friends have a heater, tell them to start saving up for a heat exchanger.
As you may know from reading this site, trichlor pucks have a pH of ~ 2.5 and will raise the cya, if left unchecked you have a recipe for algae and rotting metal. At the very least, your friends should test their water once a week, AND adjust whatever isn't right (I've seen pool owners who say that they 'DO test every week'(but don't doanything about the levels being off, "we were only told to test every week" ) In addition to this, their liner has most probably been weakened by it's acid bath.
My best advice for them is to come here and learn how to properly care for their investment, and do it in a less expensive way. Pools are expensive to install, but the upkeep can be fairly cheep when one uses the advice and methods from www.poolsolutions.com and here

I agree. This forum saved us countless hours. But what does the all red alk test mean????? In combo with the cya I'm not sure if the core alk is the problem. What do I adjust first. Is water exchange where i should start and then work on alk/ph balance?

I agree about possible damage to liner and poly. No heater in Alabama thank goodness.

Watermom? Any thoughts?

Your pH is SO low I'm amazed the vinyl liner hasn't dissolved. You FIRST need to get pH normal--add box after box of Borax until you have a ph of at least 7.0 Now you can take your other measures and you may find that CYA is quite different.

You'll have to check the liner for damage from that low pH. I absolutely agree with Waste's assessment of what happened, except for the heater.

Fix pH first, then re-measure the other items.

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Originally Posted by bluecamel

But what does the all red alk test mean?????

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I believe the Total Alkalinity test from Taylor (and others) uses a combination of "bromocresol green" and "methyl red" pH indicators that turn from green to red at around a pH of 4.5 so the fact that the TA test starts out red means that the pH is already below 4.5 :eek:

I would expect that the water is not only low in pH, but probably has much of the carbonate buffer removed from it as well (the acid from the TriChlor tabs will lower pH and the TA while the carbon dioxide will outgas quickly so I suspect the TA is also quite low). Therefore, I recommend adding Soda Ash, aka [EDIT] Washing Soda [END-EDIT] (not Baking Soda) aka Sodium Carbonate (typical "pH Up" in pool stores) since that will raise both your TA and your pH. If you follow Carl's advice and add Borax, then you'll likely also need to add Baking Soda, aka Sodium Bicarbonate.

If your TA is really very low, then adding relatively small amounts of Borax by itself will cause fairly large swings in pH. Add some, wait to circulate (an hour should be OK if the pump is running) retest pH and add more if needed, etc. If you add either the Sodium Carbonate or Sodium Bicarbonate, then you won't get as large a pH swing.

Richard

Chem_geek is not wrong, of course. Your T/A is probably 'way too low. But my recommendation for Borax is to get pH into the normal range so you can see what else is going on. Baking Soda's cheap, so is Borax.

But if you do go the soda ash route, Arm&Hammer WASHING Soda is the right stuff (Sodium Carbonate) and even cheaper (in my supermarket) than Borax per pound. The Washing Soda box is Yellow, not orange. It will be in the laundry products section.

Either way should be fine, but you MUST get pH up.

If I was ever in a situation where the chems are as messed up as they seem I think I'd try rweaking things on a small scale first, just to see if whatever you do yields the expected results. a.k.a the biggest plastic trash can you can find and scale the chemical additions accordingly. Any damage that can be done is probably already done so the additional time it takes messing with a trashcan full of pool water won't matter. Can also save a bunch of $$$.
Al

Actually 4 boxes in, but when I measured after 3 there had been no measurable change. Alk test still red from the get go and ph test still holding on sunshine yellow. We will add more the rest of the day.

I am surprised since the alk is so low, I thought the ph would swing up more quickly. I will update agin after 6 boxes.

Is there a point at which I get no change that I should start doing something else (6 boxes, 7 boxes maybe??????)?

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Originally Posted by bluecamel

I am surprised since the alk is so low, I thought the ph would swing up more quickly.

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If the pH were 4.0, then it would take about 5 boxes of Borax to raise the pH to 7.0 and almost 7 boxes to get to 7.5

If the pH were 3.0, then it would take about 11 boxes of Borax to raise the pH to 7.0 and 13 boxes to raise the pH to 7.5

So it would seem that you need to keep going. If you use Borax, then you will end up with high levels of borates in the pool. Each box of Borax adds about 3.6 ppm Boron (Borates) to the pool. So a positive side effect of raising the pH in this pool is that it will be close to having the algicidal properties of the pool that is talked about in this thread.

Richard

Please beware that a pH maintained at 3 in a vinyl pool may well have already ruined the liner.

Sorry to be the bearer of depressing news....

Thanks for the great link on the borate experiment. We are moving the ph, but not as much as I had hoped. (30 drops of base demand now puts me at 7.2).

Once I get the ph in measurable range, is the next step TA? And should I keep it around 80 like the borate experiment? Also, I will retest the CYA, but I am sure it will be over 100. If so, I need to use the CYA/alkilinity equation, right?

Advice appreciated because I do not want to over do one thing trying to correct the other.

They know that their liner is probably toast. I actually think it was pretty dead when they moved in. The previous owners have been running a very clear/high chlorine acid bath for some time. They never used the pool so they only cared if it was clear.

1) Get the pH at least into a normal range around 7.2 - 7.8 (or at least in the 7.0 to 8.0 that your test kit can measure). Do this first before anything else as the out-of-range pH is the most damaging factor to the vinyl and to pool equipment (copper heat exchangers, etc.).

2) Add sodium bicarbonate aka baking soda to increase the TA. Yes, you can shoot for a target of 80 due to the extra borates that act as a buffer and due to the very high CYA that also acts as a buffer. Also, with step 3 you don't have to shoot for high accuracy since you're going to be diluting everything anyway.

3) Try and measure the CYA by diluting with an equal part of tap water and remeasuring. Then multiply your measurement by 2. If you still measure more than 100, dilute with two parts tap water to one part pool water and try again and multiply by 3, etc. Based on your CYA measurement, you will have to do a drain and refill to lower the CYA. However, that's a pain to do and will dilute all of your other chemicals so you might just keep your fingers crossed and hope that the CYA will get lower over the winter (some users see this occur) and then deal with the high CYA in the spring, but with such extraordinarly high CYA I doubt it will get lowered enough. With the lower water temperatures, the risk for algae is much less.

And of course immediately stop using TriChlor tablets as the source of chlorine. Switch to using bleach and maintain chlorine levels using bleach (or chlorinating liquid). Unfortunately, with the very high CYA levels a high chlorine level will be needed, but at least with the winter low water temperatures, the risk for algae will be low. You mention the CYA/alkalinity equation, but I think you mean the chlorine/CYA relationship as found in Ben's Best Guess CYA Chart. Let us know the actual CYA number when you get that figured out and we can tell you the chlorine level to maintain (or perhaps to just do a partial drain/refill now if the CYA is astronomical).

It's a good thing these people never used the pool. It truly sounds like an acid bath, though most carbonated beverages have a pH between 2.4 and 3.2. Nevertheless, the worst effect of swimming in such an acid pool would be on the eyes (that would sting like crazy and could even be harmful) while certain swimsuit fabrics would likely degrade. I'm sure it's not good to expose skin to such an environment, but don't know how long it takes to cause problems.

Hang in there -- you're doing great. And as Carl said, this pool may be totally ruined as the acidity may have destroyed the vinyl as well as any metal parts, especially copper as would be found in a gas heater.

Richard

Yeah here's hoping it's really thick vinyl so there's enough of a layer that isn't damaged, otherwise it's all for naught. Acid softens vinyl--some of the people who used the "slug method" to try lowering T/A found this out--you can SEE the vinyl wrinkling where the acid is destroying it.

Swimming in that? You might end up skinny-dipping when it dissolves your suits...depending on your POV this could be a bad thing:eek: , or a good thing:D :D !

I hate to be pessimistic, but I think this liner, if it's not toast, will have a much shorter life.

But, as Richard said, you are doing everything right.

Thanks guys. I will try the dilution cya test. My neighbors' heads are swimming from all the stuff I am throwing at them. But they are sending in their funds to become members and are on their way to being converts. I think they will drain some in the summer, assuming their liner makes it. They have been pounding the pool store chlorine the last 2 months since they moved in.

I know you have heard it before but, as always, you are great.