pH Preparation for Borates

[hleapha]

Getting ready for borates:

Yesterday I lowered my TA to 80 with MA. Resultingly, my pH dropped to ~6.8. In the sticky it said to get the pH to ~7.5. I was wondering why you can't just go ahead and start adding borax. It seems to me that borax would raise the pH anyway and would just mean I'd use less MA to balance the borax.

Any thoughts?

-Henry




-20,000gal, vinyl, sand filter

 

[dmanb2b]

your thoughts are correct...once the PH gets to the 7.5 area, then you can start adding the mix of borax and MA needed to stay PH neutral

 

[JasonLion]

If you add borax to bring your PH back up, your TA will also come back up. You want to aerate to bring the PH up before adding borates.

 

[reebok]

your thoughts are correct...once the PH gets to the 7.5 area, then you can start adding the mix of borax and MA needed to stay PH neutral

this is not what he was thinking. he wants to add borates right now, without raising ph. I had the same thoughts. have you read the borate sticky? I asked this same question.
so-you-want-to-add-borates-to-your-pool-why-and-how-t4921-60.html

 

[dmanb2b]

your thoughts are correct...once the PH gets to the 7.5 area, then you can start adding the mix of borax and MA needed to stay PH neutral

this is not what he was thinking. he wants to add borates right now, without raising ph. I had the same thoughts. have you read the borate sticky? I asked this same question.
so-you-want-to-add-borates-to-your-pool-why-and-how-t4921-60.html

why would he want to keep his PH at 6.8?

Good point Jason.

 

[hleapha]

Thanks for the link, I looked through a few pages but missed this one. We had almost identical questions.

I saw this:
reebok wrote:
I have a question about raising the pH before starting. since it's a pain and time consuming (for some) to do the aeration, once one reaches the correct TA level, why aerate to increase the pH, when you have to turn around and buy gallons of acid to keep the pH down? why not just use less acid during the borax addition and let the borates raise the pH? thanks.
Reply:
The final result would be a higher TA level than you want. The difference wouldn't be all that large, but the TA level would be higher this way.

Using aeration to raise the PH will not change the TA level. Adding borax to raise the PH will also raise the TA level.


I see that the TA level will be higher than desired when done, so why can't you add MA to lower TA and aerate AFTER adding the borax? I'm guessing b/c it is harder to adjust TA once finished with borates.

 

[JasonLion]

You can do it in either order, it is just more annoying to do it after you add borates.

 

[reebok]

why would he want to keep his PH at 6.8?

he's not saying that. he's saying "my TA is in range, why should I wait to add borates simply to raise my ph when the borax is going to do it anyway, and I have to buy a lot of acid to keep the ph down." it seems counter-productive, which is what I was wondering when I did it.

 

[dmanb2b]

got it...I wasn't focused on the TA of 80 being the goal #...my bad. Although, I wish I had more background b/c I do not see any SWG or water feature listed on the OP's signature, hence why I wasn't sure what the TA goal was.

I see to many folks here shooting for a specific low TA when everyone's "sweet spot" will vary. For example my TA happens to be 80 with a SWG and 50ppm Borates...My PH has been between 7.4-7.6 rock solid...virtually locked. On the other hand, before I had the SWG hooked up, I made the mistake too of lowering TA to 80 and I had to keep adding borax as my ph kept dropping.

Thinking back I should have answered that he could chose the route suggested, but it would have resulted in a slight TA increase to 90 or 100...I understand...good point.

 

[reebok]

my TA was 80 and ph was 7.4 before I added. the TA went up to 100 after borates.

 

[hleapha]

Thanks for the help. I'll just aerate now and raise my pH back up. I don't think a pH of 6.8 will corrode my pump but idk. It sounds like I would go through more acid in the long run by lowering the TA after borates than adding borax to up the pH.

I sure hope after I'm done with this process I go through less bleach. I have to add a gallon a day to combat losing 2-3ppm/day. I guess that South Carolina sun eats it up.

 

[chem geek]

I sure hope after I'm done with this process I go through less bleach. I have to add a gallon a day to combat losing 2-3ppm/day. I guess that South Carolina sun eats it up.

In this post you listed CYA as 25 ppm. That would explain why your chlorine doesn't last very long in direct sunlight. As was noted in the thread with that post, you should raise your CYA level and maintain a higher FC level along with it. This will reduce the amount of chlorine you use. Try 50 ppm to see how that goes. If the chlorine usage is still too high, you can go up to 70-80 ppm, but would need to maintain a minimum FC of around 6 ppm in that case.