# Thread: Is a gallon of muriatic acid per week ok?

1. ## Is a gallon of muriatic acid per week ok?

I've been using about a gallon of muriatic acid per week to control pH and I'm just wondering if this is ok. I measure pH everyday, but I usually add the acid once per week, right after I go through my full weekly battery of tests on Saturday.

Saturday morning, I'll get done with my testing and almost consistently find the pH up around 8.2. I'll add a gallon of muriatic acid, and test again a few hours later to find it at 7.2. The reason I add once per week is because I really like to limit my exposure to the stuff and only want to deal with it once per week.

However, I'm just wondering if it seems normal for my size IGP to be using a gallon per week.

FC = 5
CC = 0
TC = 5
pH = 7.5
TA = 100
CH = 250
CYA = 40
Salt = 2000
Borate = 31.6

2. ## Re: Is a gallon of muriatic acid per week ok?

If it's a new pool that's normal--at least that's about what I used for the first few months.

Now I use about a quart a week, but I have a SWG and lots of aeration.

3. ## Re: Is a gallon of muriatic acid per week ok?

PoolMath say that for each gallon of 31.45% acid in a 23k gal pool at TA=100, TA will decrease by 22. Just wondering if you are seeing a this level of TA decrease each week? Also wondering what TA your fill water is?

4. ## Re: Is a gallon of muriatic acid per week ok?

Originally Posted by HouTex
If it's a new pool that's normal--at least that's about what I used for the first few months.

Now I use about a quart a week, but I have a SWG and lots of aeration.
Hi HouTex. Yep, I forgot to mention this is a brand new pool finished mid-June of this year. I was thinking the rise in pH might have something to do with the new plaster, but wasn't sure.

Originally Posted by epro05
PoolMath say that for each gallon of 31.45% acid in a 23k gal pool at TA=100, TA will decrease by 22. Just wondering if you are seeing a this level of TA decrease each week? Also wondering what TA your fill water is?
epro5: I have not tried measuring TA directly after dumping in the gallon of muriatic acid. I've only measured pH about three hours after and then remeasured TA the following week with the rest of my testing battery.
I'm going to try testing TA directly after adding muriatic acid this coming weekend though and see what drop I get. I'm also interested in the TA of my fill water. I'll try that as well.

5. ## Re: Is a gallon of muriatic acid per week ok?

You should be adding the acid more often, do not let the pH rise above 7.8 as you are risking scaling when the pH is above 7.8. With time the acid demand will slow down as the plaster cures.

6. ## Re: Is a gallon of muriatic acid per week ok?

Originally Posted by ping
You should be adding the acid more often, do not let the pH rise above 7.8 as you are risking scaling when the pH is above 7.8. With time the acid demand will slow down as the plaster cures.

I was going to say that. Smaller additions several times a week are much better on the pool and equipment than huge fluctuations once a week.

7. ## Re: Is a gallon of muriatic acid per week ok?

Originally Posted by ping
You should be adding the acid more often, do not let the pH rise above 7.8 as you are risking scaling when the pH is above 7.8. With time the acid demand will slow down as the plaster cures.

8. ## Re: Is a gallon of muriatic acid per week ok?

Originally Posted by tim5055

I was going to say that. Smaller additions several times a week are much better on the pool and equipment than huge fluctuations once a week.

9. ## Re: Is a gallon of muriatic acid per week ok?

I needed to lower PH so I bought some muriatic acid and started reading up on how to use it, I was frankly scared after reading the instructions people posted about using it, went to HD and got some PH down, don't care if it costs a couple of extra bucks

so I have 2 jugs of MA in North Atlanta (dunwoody) if anyone is interested

10. ## Re: Is a gallon of muriatic acid per week ok?

That's my pool's diet with new plaster, but my pool is twice as big.

11. ## Re: Is a gallon of muriatic acid per week ok?

Originally Posted by WWells
I needed to lower PH so I bought some muriatic acid and started reading up on how to use it, I was frankly scared after reading the instructions people posted about using it, went to HD and got some PH down, don't care if it costs a couple of extra bucks
You are better off with the muriatic acid since the PH down add sulfates in the water and in long run you might regret it. The hydrochloric acid is normally found even in human stomac so do not hesitate to use it. It is better for the pool and cheaper too.

12. ## Re: Is a gallon of muriatic acid per week ok?

I bet my comment is one of the ones you are referring to. I use and like 31.45 because it minimizes the volume I have to use, but yes, it's strong stuff.

I believe Home Depot near me carries a weaker one. Lowe's also has a second bottle I have never read the label of. Look for a more dilute concentration than 31.45...like 15ish.

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•