High Ph a problem?

[Condo Steve]

Hi,
Just took over pool duties in a 15,000 gal. inground plaster pool at my home. My Ph is pegged high on my phenol test. What problems are associated with too high Ph? I am adding 30 percent muriatic each night, about 8 oz. that I dilute with a bucket of pool water before pouring into the pool. Three nights and it hasn't moved from pink. Pool is open year round in S. Florida. Water looks clear. Waiting for Ben's kit to test CYA levels and extablish a proper maintenance level of Cl. Right now I pour in about a quart of 6% bleach each night and the OTO reads about 1.0 to 1.5 after an hour or pump running.
Thanks,
Condo Steve

[Watermom]

What ph reading are you getting?

[Condo Steve]

I don't have the kit in front of me, but I believe that the indicator tops out at 8.2 (pink). I would like to get out of the maximum indicated range and back near the middle. Pink could be 8.2 or anything higher.
I know that low Ph is problematic, but is a significantly higher Ph a problem causer?
Thanks,

Condo Steve

[Watermom]

Scaling is often a problem with high ph. Keep working to get it down. Aim for 7.4-7.6.

[mphare]

I don't believe 8 oz is enough muriatic to get much of a difference in a 15K pool.
I have a 13.5K and I usually add 2 to 3 cups of muriatic acid to get a few tenths of pH difference.

[Watermom]

Do a search for any post made by mwsmith2 who is one of the members of the forum. In his signature is a link for a bleach calculator that you can download. Once you do, if you will click in the upper left corner "more calcs" you will find a calc that can help you determine how much muriatic acid to add for a desired ph change per volume.

[Condo Steve]

Thanks a bunch for the replies. I know that 8 oz. of muriatic is not much to my pool. However, the 8 oz. Solo cup is a pretty handy measuring device. I don't know the exact Ph, just that it is 8.2 or higher. That's why I didn't use BleachCalc to calculate a dose. I didn't want to yo-yo past 7.4 or so and I thought that drastic Ph changes can screw up your water, (make stuff precipitate, go clowdy, etc.).
8 oz. by 8 oz. I'll find 7.4 or 7.6 eventually. I just throw in a dose each night and test and redose the next night. I'll get there.

My other question was: What are the consequences of having a sky high Ph? Are there any downsides besides irritation to swimmers?

Thanks again,

Condo Steve

[Watermom]

As I mentioned in my post further up the thread, scaling can be a problem with high ph.

[Condo Steve]

Thanks,
No scaling noted. I'll continue till I get a measurable phenol score or Ben's kit arrives.

Condo Steve

[HooStat]

If you have a salt chlorine generator, then you don't really have to worry about adding too much acid, because Ph will go up and may be why you can't get it down very easily. If not, then ignore this comment.

Another thing you can do is to use the acid demand drops if you have them and see how far you are above 8.2. After you do your test, add them one at a time until the water changes to something immediately below pink. Then do the same thing the next day. Hopefully it will take fewer drops each day to turn the water. If not, then you may need to be adding more acid each day to get you there since you are not making any progress.

[HooStat]

I just found this on google -- an old post on poolforum. It may be the easiest thing to do to get your pH correct. Sorry, but I don't know who posted it since the cached version isn't very easy to read. Note that you have to adjust for the size of the pool.

Here's what I started doing. Its pretty accurate.

I take a one gallon sample of pool water. Then I add one drop of 20% muriatic acid, mix and run pH. I repeat until the pH is what I want. For every one drop of acid I added to get the pH right, I add a quart of 20% muriatic acid. This is for a 20,000 gallon pool.

Here's the calc:

Fact: 20 drops = 1 milliter
Fact: 3785 milliters = 1 gallon

(#drops added X 20,000 gal)/20 drops per milliter)/3785 milliters per gallon = Gallons of acid to add to pool.

Example: (1 drop of acid X 20,000 gal)/20/3785 = .26 gallons acid

[Condo Steve]

Hoostat,
That's a gem. I keep waiting for the kit to arrive so I can just measure my real Ph and do a calculation on BleachCalc for acid dosing. Watched pot never boils.
I'll give it till Friday, then I'm in on the gallon-o-pool-water method.

Thanks a bunch for the replies. I almost look like I know what I'm doing poolside.

Condo Steve