Hard to get Ph down & leave TA alone...

[batsona]

I added enough Baking Soda to get TA up to 90. Every time I test the Ph, it's around 8.0, so I put some dry acid in. Over the last week, I've put about 3/4 of the entire container into the pool (4,000gal), and I can barely keep Ph below 8. Just tested TA again, and now it's back down to 70.

I just put another 1/2 box of soda into the pool.

I don't have much trouble with Free & Combined Chlorine - they're all where they should be... I have a salt-chlorine generator if it means anything. Also, I have alot of aearation (sp?) too; my return is very near the surface & gurgles

Am I doing this right?

 

[JasonLion]

With a SWG you want the TA down around 60 or 70. Having TA above that is what is causing the PH to rise so quickly.

 

[batsona]

Hmmm.. Alrighty -- I can deal with that. I'll keep TA around 60-70, and see if i can get the Ph down to 7.8 or 7.6 or so.

I'm having much better luck this season with crystal clear water with the tips I've learned here, along with my machine that makes Chlorine for me!

 

[duraleigh]

I'll keep TA around 60-70, and see if i can get the Ph down to 7.8 or 7.6 or so.

Both TA and pH will come down nicely if you use muriatic acid and will do so in 30 minutes.

 

[batsona]

OP here... Still having horrible problems keeping Ph down. I've got the dry acid (Sodium Bisulphate), and I put in 1/2 cap-full every other day. I tested TA, and I'm down at 40-50 ppm. A new development: My cholorine generator gave up the ghost (new one on its way). I now maintain Chlorine via bleach. Is there anything chemically happening in the pool that's weird, because I have plenty of Salt, as well as using Bleach to maintain Chlorine? I used Sodium Bicarbinate (Soda), and got TA up to 80ppm, but me putting acid in every other day is causing a long slow slide for TA....

I admit that it's time to vaccume the pool, but would the presence of 'bioloical' material in the pool screw with Ph so badly?

Using bleach, I maintain Chlorine between 1 and 3ppm. Ph seems to always be 7.8-8.0 -- been a long time since I've seen that nice peach color on the tester. Its usually pink all the time....

 

[waskydiver]

How often are you testing and adjusting your TA/pH?

It kinda sounds like you may be chasing it too agressively.

TA likes to find its own sweet spot. If it's too high, then it will push your pH higher. The higher pH will be driven down by acid, lowering your TA to where it wants to be.

I would just maintain your pH at a comfortable level. It sounds like at your acid demand, it might be easier a little higher... maybe 7.6. Then, let your TA come down to where things seem to stabalize.

Low TA, in and of itself is not a problem, however, you want to look out for two things:

1) Make sure your CSI is not getting too low.

2) Make sure that your pH is stable.

Even if your CSI is getting too low, you can correct that with calcium if you are happy with the stability of your pH.

And, if you are finding your pH is bouncing around a bit, you might want to add some borates to provide some additional buffering independent of your TA.

Bottom line is that I would generally only suggest correcting your TA in response to a particular problem (Low CSI, unstable pH), and not just trying to get the numbers.

 

[batsona]

I guess you could say my Ph is stable, if "consistently too high" is called 'stable' To answer the question, no the Ph doesn't bounce around; I usually find it between 7.8 and 8.0.

About a month ago, I was adding baking soda until TA hit 80. Then over the last month, I've been adding Sodium Bisulphate (dry acid) every other day to try to keep Ph under 7.8 or so. Then, I find that TA is down around 45-50 again.

 

[waskydiver]

If it were me, I'd:

1) Add some borates to provide some additional buffering.

2) Keep your pH at about 7.6, without worrying about where your TA is.

If you have a plaster pool, we may need to take into account your CH to get a CSI reading. If your CSI is too low, and you have plaster, I'd bump up your CH.

Otherwise, the only reason that you'd need to worry about your low TA is if you have a hard time keeping your pH stable. But, hopefully, the borates will help that, and you'll be OK.

 

[batsona]

Pool is vynl actually. When I add the borates, that drives up Ph, from what I've read, forcing me to use more acid to bring it down. --but what you're saying is that after all is said and done, the Ph will be easier to control, after I get the borates in, and re-adjust Ph?

 

[waskydiver]

Yep... that's pretty much it.

Just follow the instructions here:

so-you-want-to-add-borates-to-your-pool-why-and-how-t4921.html

Afterwards, just maintain your pH, and let your TA find its own sweetspot. Only if you find that you are having problems with your pH bouncing around will you need to increase your TA.

 

[jasonknox]

Borates were not the magic bullet for me. I still have rising PH. I keep waiting for my TA to come down from 70/80 so that my PH will stabilize but it hasn't.

 

[faby3003]

In your original post you mention you have a lot of aeration due to your return jets. I would recommend trying to eliminate that.

 

[RobbieH]

Pool is vynl actually. When I add the borates, that drives up Ph, from what I've read, forcing me to use more acid to bring it down. --but what you're saying is that after all is said and done, the Ph will be easier to control, after I get the borates in, and re-adjust Ph?

You could by Boric Acid if you'd rather just do it all in one addition. I found it was cheaper to add Borax and MA though.

 

[batsona]

From what I read, adding borates will send Ph in the opposite direction from what I want - Borates will raise Ph -- I need it lowered. Most every day when I come home from work, I'm pushing near 7.9 - 8.0 or so. That nice peach-color in the tester (7.6) never stays for very long - 24h later, I'm getting pink again. I tested TA, and it's ~40ppm.

If I wanted my TA higher, I'm supposed to add Baking Soda (will raise Ph and TA) --Then add acid to bring down Ph, while leaving TA pretty much where it is. --This is exactly what I followed. I added Soda until TA was 80. Then every other day, I add acid to keep Ph down. After a month of doing that, my TA is down to 40, and my Ph always seems to be 7.9.

 

[JamesW]

After a month of doing that, my TA is down to 40, and my Ph always seems to be 7.9.

That's fine, leave the numbers there, and stop fighting them. Stop raising the TA. If the pH goes to 8.0, or higher, then only lower the pH to 7.8 or 7.9.

What is your calcium hardness and cyanuric acid?

 

[batsona]

I'm quoting these from memory.. CYA is around 30, and Total Hardness is somewhere between 200-400 I think. BUT: this is read from test-sticks, because my chemical tester doesn't include CYA and TA tests.

 

[Bama Rambler]

Then you need a better test kit.

I think you read something wrong. Anytime you adjust the pH down with acid you're going to lower the TA also. It's a fact of life. And you actually want the TA to come down to help control the rising pH.