Question about testing for TA and bringing it down.

[wickflair23]

On my 3rd water fill in my 410 gallon Tub. TA in our city water is nearly 400 out of the hose which requires a lot of acid to bring it down. My process is to add 1-3oz every 10 minutes or so with jets on until it gets to 40-60 and Ph is at 7.4-7.6 stable. This takes forever. Per my calculations it took around 28oz. Would there be an issue to start with a bigger does of say 10-14oz and then work my way up there to save some time or is that risky?

Also, I am still learning the technique when doing the drop test, but what I experienced last night made me question what my actual PPM was at. When I got to the 4th drop (40PPM) the solution was very pink. However, I added a 5th drop just to be sure and it got even Brighter pink? Would that mean I am some place between 40-50 or at 50? Or even at 40 because it was very pink at that point?

Thank you all for all the help thus far!

 

[pjt]

I added a 5th drop just to be sure and it got even Brighter pink? Would that mean I am some place between 40-50 or at 50? Or even at 40 because it was very pink at that point?

Keep adding drops until there's no additional color change. If the drop results in color change, count it. If the color remains the same, don't count the drop and the test is complete. Are you using a SpeedStir or other type of stirring device?

 

[wickflair23]

Keep adding drops until there's no additional color change. If the drop results in color change, count it. If the color remains the same, don't count the drop and the test is complete. Are you using a SpeedStir or other type of stirring device?

Yes, I have the speedstir.

 

[mknauss]

Would there be an issue to start with a bigger does of say 10-14oz and then work my way up there to save some time or is that risky?

Very risky. Could destroy the heating element and any other metal items in your spa.

 

[wickflair23]

Very risky. Could destroy the heating element and any other metal items in your spa.

Okay, good to know. Is there a safe amount or is it only a few oz? Like would say 8oz be okay? It took me all night to get it down and that is very time consuming.

 

[mknauss]

Lowering pH below 7 is risky.

 

[wickflair23]

Lowering pH below 7 is risky.

Not trying to lower it below 7. I want it at 7.4-7.7, but I have to add a boat load of acid to get my TA down otherwise I sit around 8-8.2

 

[mknauss]

Likely your water pH will always be near 8. You will struggle to maintain the low pH you want.

 

[wickflair23]

Likely your water pH will always be near 8. You will struggle to maintain the low pH you want.

As I mentioned this is my 3rd fill. If I get TA down to 40-60, PH is fairly stable. Only have to add a few oz of acid every 3-4 weeks to knock it back down some. I am just sick of taking all dang day to get the TA in check.