Dealing with scale problem

[beaverplt]

Hi all, I've just opened my 25,000 in ground pool. The first thing I did was shock it and add some algaecide to clear it up. Testing my water this morning (with a test strip) I found that my PH was normal but my TA and Hardness were both very high. Previously when my TA was high, my PH was also. This is a first for me. I'm new to this forum, but I've learned by searching around that;
A: testing with a strip is not the best way to manage pool chemistry.
B: My problem is not unusual.
C: TA takes a while to lower.

I read the link in "Pool Solutions" by Ben Powell about lowering TA. He says to use small doses of acid and to aerate the pool. My questions are, what is a "small dose" for a 25,000 gallon pool? How often do I add the dosage? How often do I test?
Thanks all

[CarlD]

We cannot recommend you take that step unless we know something about your pool situation.
Is it a hard-sided or vinyl lined pool?
What is your chlorine level?
What is your pH reading?
Your T/A reading?
Your CH Reading?
and your Stabilizer/CYA reading?

If you have a vinyl pool and your T/A is, say 180, you are fine. Vinyl pools only become problematic when T/A approaches 200 and CH is over 400, at which point it gets cloudy. But a concrete/tile or plaster pool you need to keep TA below 120-125 and CH between 200 and 400.

[beaverplt]

Sorry, Took a while to reply. (Darn job gets in the way) I forgot the details. My pool is vinyl lined. Keep in mind that I've been testing with test strips, so my numbers won't be accurate. My chlorine levels are nil. PH is at 7.2. TA is over 240. I'm guessing CH is hardness? That's at 400. My CYA reading is in the normal color range, but I forget the numbers.

[PoolDoc]

1. Read http://pool9.net/alk-step/. That will explain how to fix the problem. Read http://pool9.net/ma/, which will tell you how to safely handle muriatic acid.

2. Order a K2006 http://pool9.net/testkit/; you'll need it to manage the process as you get close to the end.

Welcome to the forum!

[beaverplt]

Thanks for the links. The one thing missing though (unless I missed it) is how much acid to add and how often. When I had a problem with high PH and TA a few years ago, the local pool dealer told me to add 1/2 gallon of acid twice a day and keep the pump running 24/7. I've started the process using that advice. With the PH being normal I've added a submersible pump and aimed the return jets upward to aerate the water.

[PoolDoc]

I'm not sure how many gallons you have, but 1/2 gallon is a lot for most pools.

I don't care what your dealer told you; do NOT dose by "X amount on Y interval"! Test your pH, and hold it to 6.8 - 7.0 by adding acid AS NEEDED!

Low pH (<6.0) will damage ALL types of pools.

[beaverplt]

My pool is 25,000 gallons. Since I started aerating, my PH has stayed around 6.8 as I've added acid. I've been adding 1/2 gallon at a time twice a day for 2 days for two gallons total. This morning my PH is at 6.8 and my TA is still around 240. With the TA so high I'm hesitant to shock the pool or add any algaecide. The algae in the pool is clinging to the vinyl so tightly that no amount of scrubbing or my pool cleaner is removing it. I live in Wisconsin where the cold weather has not really relaxed it's grip. Could the cold temps be part of my issue?

[BigDave]

The pH may be quite lower than 6.8 if 6.8 is the lowest on the comparator. Does your test kit have a base demand test? We seldom recommend using Acid / Base demand tests but in this case I'd like you to be sure it's safe for the pool.

[PoolDoc]

What Dave said. NOW!

STOP ADDING ACID!

If you don't have immediate access to a acid demand kit, go to Walmart and buy out their borax (up to 20 boxes). Turn your pump on high speed, and leave it on. Add 2 boxes of borax every hour -- slowly, to the skimmer -- till you have a pH ABOVE 6.8. It doesn't have to be much above, but enough so you can tell a difference.

THIS IS URGENT! YOU MAY BE DESTROYING YOUR LINER AS I TYPE!

Given the way you are dosing, and testing, your actual pH may be 5.0 or even 3.0. If it is, it won't take long to do PERMANENT damage to your liner. And unlike liners bleached by high chlorine, the damage done by low pH is MORE than just cosmetic.

HURRY!

[beaverplt]

Finally got a testing kit to use instead of the strips. My PH tested at 7.2 today using the kit. Yesterday, a test strip read 6.8. Considering I am aggressively aerating the pool, that makes sense to me. BUT, My TA tested at 80 using the kit. The strip showed 240 yesterday. My hardness tested at 210. The strip yesterday; 400. WOW! That kind of difference makes me understand why so many of you in this forum dislike the strips. How can they be that far off? Needless to say, I'm never, ever, going to test with anything but a kit again.