Rising pool pH with SWCG

[spibill]

My pool is has an SWCG, and I am having a problem with the pH constantly rising. What can I do?
Muriatic acid is relatively cheap, and once you learn to handle it, not hard to use. So it's not really that much of a problem. But, you can often reduce the pH rise by the following steps:

• Increase the CYA level to 70 ppm or higher, which will reduce SWCG on-time.
• Decrease the TA to 70ppm or lower. (Increase the calcium to compensate on concrete pools).
• Add 50 ppm borates (borax) to help stabilize the pH. (This will require a one-time pH adjustment, since the borax is basic, and causes a pH rise itself.)

(from http://www.poolsolutions.com/gd/swim...ators-faq.html )

I have this problem. How do I determine how much borax I need for a 5,000 gal pool/hot tub?

[PoolDoc]

That's a big spa! What do you have, a swim-spa?

Regardless: add 5 boxes of borax, and have two gallons of muriatic acid on hand to compensate. Do NOT add more than one box at a time, before adjusting the pH and DO add it slowly, via the skimmer. (Borax can solidify and plug pipes!)

However, with a SWCG on a stand-alone spa, you're likely have more of a problem with this, than on most pools. The steps quoted will help you manage it, but are unlikely to make the problem go away.

BTW, thanks for the subscription.

[spibill]

Thank you for your response. I'll get the materials and follow your advise. Just to clarify,the spa flows into the pool and both are on the same system unless I select spa then only the spa is connected to the system -pump,filter,heater,SWCG. Otherwise in non spa selection the spa is 1 of 5 Caretaker returns to the pool/spa. I currently have to add a quart to 2 quarts a week of muriatic acid. I read an article that said some pools can have a higher PH, (up to 7.8 or 8) then normally recommended and not have any problems, but can not find any info as to weather this works if you have a SWCG. Do you have any comments on this?

[PoolDoc]

Hold the horses!

If your spa "is 1 of 5 Caretaker returns", then the water for the spa and the pool is mingled, and you have to treat BOTH, as one unit.

Let's take a step back.

1. Order a K2006 or K2006C kit, and let's find out what's really in your pool. (Links for Amazon purchase in my signature -- do NOT confuse K2006 with K2005!)

2. Take, and send, pictures of the pool, spa, piping, heater, & valving to 116085760037372010926.sophocles@picasaweb.com with the subject, "PF thread #14386" and I'll post them. (That link will expire, by the way. It will be good for at least a week, however.)

3. Then, after we understand what's in your water, and how your pool and spa are connected, we can make better recommendations. That goes for high pH too. Without knowing what sort of equipment you have, and what your alkalinity and calcium levels are, we can't make good recommendations there.

[spibill]

Ordered kits today. Will work on pictures. Thanks

[PoolDoc]

Hi Bill;

Waterbear, one of the most experienced posters here, took the time to write up a detailed alternative approach to using borax for you. However, his post included a couple of points of chemistry I'm not sure about, and more significantly, an operational recommendation that I've avoided in the past.

It sounds like you've handled muriatic acid enough to know about the fumes -- they are not nice, and can be both rather dangerous and quite frightening to pool owners. Anything that increases the exposure of the acid to the air -- such as pouring the acid into a measuring container -- dramatically increases the quantity of HCl gas (the fumes are actually the acid, itself, which is otherwise dissolved in water) present in the atmosphere. For this reason, it's been my policy, and one I've encouraged my moderators to follow as well, to avoid ANY instructions that required pool owners to attempt to measure acid quantities exactly, since this normally means pouring into a measuring cup.

The moderators and I have discussed this, but I think we need to have a discussion among the larger group of contributors to the site, a group in which Waterbear is certainly a leader, and come to a consensus we can operate by for the safety and comfort of PoolForum uses generally. So, I moved Waterbear's post to the China Shop, since the follow-up discussion is likely to get rather detailed, and to NOT be focused on your particular issues.

You can read Waterbear's post here:

http://www.poolforum.com/pf2/showthread.php?14387

and my guide to applying muriatic is here:

http://www.poolforum.com/pf2/showthread.php?13111

Hope all works well for you.