TA not adjusting

[MaxAcceleration]

Hi guys,

I changed my pool liner myself two weekends ago and it looks great.

Now I'm trying to balance the new truck delivered water (3 tankers @ 5800 gallons) and the remaining from rain/filtered well.

ph: 7.4
TA: 250
FC: 5.0
CC: 0
CYA: 40
CH:150
Temp: 82

My water looks great, crystal clear, however I'm wanting to add borates to provide that crystal sparkling water and all the other reasons listed in pool school.

The problem is I've added 3 gallons of muriatic acid thus far and my TA has remained at 250 no matter what I do.

I have an aeration spray fountain on one return and the other two returns I have pointing up breaking the surface. My PH is consistently cycling from 7.8 back down to 7.2 after each addition of acid (one gallon of acid each cycle).

I've been at it for 3 days now. Is it possible the TA is maxing out on the test kit at 250? (ie... maybe it's really 500 or something and it really is coming down, just not measurable?)

Thanks,
Jamie

 

[jblizzle]

I do not think the TA test would max out, although I am not sure I have an explaination for you.

Try testing your tap water and see what TA it has.

 

[GOONiE]

if pH is rising to 7.8... keep adding acid. TA should drop eventually.

I'm only 24 hours after MA to lower TA, so far no change. My pH did change from 8 to 7.4 with 2 qt of MA.

 

[Texas Splash]

There's a TA monster in that part of the country. Some have a TA of 400+. Crazy. When you knock the pH down with acid, try aiming for 7.0. Some people find that you have to really kick it in the gut to help pull the TA down with it - then aerate. It's stubborn. But just that little bit of difference might help crack the shell of that TA.

 

[MaxAcceleration]

Try testing your tap water and see what TA it has.

Tap water came back at TA=350. PH =7.0 (that blows my theory that the test kit is maxing out at 250 - lol)

Ok, I'll continue cycling down to 7.0 and attack the TA monster. I usually just leave the TA alone, but figured I'd give the Borates a try this year. fyi, haven't added any borates yet.

I just can't wait to see the faces on Walmart employees as I buy 21 boxes of Mule Team Borax. LOL

 

[Texas Splash]

I just can't wait to see the faces on Walmart employees as I buy 21 boxes of Mule Team Borax. LOL

Wait until the day comes if you ever have to SLAM and buy several gallons of bleach at once. I suggest buying some duct tape, a shovel, and a ski mask at the same time just for the sheer entertainment value of everyone's face when you checkout.

 

[MaxAcceleration]

Wait until the day comes if you ever have to SLAM and buy several gallons of bleach at once. I suggest buying some duct tape, a shovel, and a ski mask at the same time just for the sheer entertainment value of everyone's face when you checkout.

LOL - yeah, I usually buy 3 cases at a time to fill up my 15gal jug to supply the Steiner pump, they don't flinch at the pool store, which is the cheapest place around here to buy it at 2.79 a gallon for 12% ---- 128*0.12=15.36 ------- 2.79/15.36= 0.1816 or 18cents/CL Oz.

I do like the ski mask, duct tape, and shovel though - although I'd probably end up getting shot in return.

 

[JamesW]

I would suggest using boric acid for borates. It's much easier.

Once you add borates, you can actually add more acid per dose.

1 gallon of 31.45% acid will lower the TA in your pool by 21 ppm. 3 gallons will lower the TA by 62 ppm.

If the TA doesn't seem to be moving, maybe it's test error or maybe the acid is not full strength.

Is the acid 20 baume or 31.45%?

 

[MaxAcceleration]

Is the acid 20 baume or 31.45%?

It's 31.45

I would suggest using boric acid for borates. It's much easier.

Interesting, I do see it in pool calculator as an option. Where do I buy that from? Looks like I'd need 57lbs of that.

3 gallons will lower the TA by 62 ppm.

Yeah, it's almost like it's in some sort of TA lock or something. I'll just keep adding - I bought 3 cases of MA so I'm ready for this fight.

Once you add borates, you can actually add more acid per dose.

Are you saying to add the borates now? I thought I'm supposed to adjust TA first? Maybe this is an exception case?

Thanks,
Jamie

 

[JamesW]

Dudadiesel.com for boric acid.

You can add it before or after lowering TA. It's about the same either way.

For example, without borates, you add 49 oz acid to lower the pH from 7.8 to 7.2.

With borates, you add 99 oz acid to lower the pH from 7.8 to 7.2. So, you can add twice as much per dose, which drops the TA twice as much.

Or, you can dose 50 oz at a pH of 7.5. So, you're dosing earlier.

The pH rise is slower with borates. So, the net effect is that lowering TA with or without borates is about the same.

 

[MaxAcceleration]

Dudadiesel.com for boric acid.

Thanks! Will get it a try.

For example, without borates, you add 49 oz acid to lower the pH from 7.8 to 7.2.
With borates, you add 99 oz acid to lower the pH from 7.8 to 7.2. So, you can add twice as much per dose, which drops the TA twice as much.
Or, you can dose 50 oz at a pH of 7.5. So, you're dosing earlier.
The pH rise is slower with borates. So, the net effect is that lowering TA with or without borates is about the same.

Got ya. I plugged in my numbers and came back with 139oz with 0 borates and 188oz with 50ppm borates.

Update on the TA. I added 4th gallon of MA before going to bed last night. This morning PH was at 7.5 and alk at 225 - dropped a whopping 25ppm. Continuing to add.

One question I do have is should I be turning off my Stenner injection pump? I've been running it 8 hours a day, maintaining 5ppm of Chlorine. If I do turn it off, how would I maintain chlorine during the process? Maybe add when it gets to 7.2 and wait a bit before adding more MA? Maybe that explains why TA hasn't been lowering like it should?

 

[JamesW]

I would leave the Stenner working. No need to turn it off. Maybe turn it off just when you pour the acid into the return stream.

On the acid additions, I had the wrong TA plugged in. With the correct TA, my numbers match yours.

As the TA drops, the amount of acid added per dose will decrease.

 

[MaxAcceleration]

Update: 11 gallons of MA later and I'm at 70ppm. I added 55lbs of Boric Acid from DudaDiesel and I'm good.

Had 3.13" of rain last night so the PH is actually low right now 7.2, so I had to send some water to waste and I'm aerating a bit to bring it back up.

It did *seem* to make a difference by turning off the Stenner chlorine pump while adding. Not sure, but that's about the time I started noticing a difference.

Thanks a lot for the help guys. Now time to see if adding the borates is all worth the hassle.

 

[JamesW]

Ok, I suspect that the pH will be pretty stable from here.