Borates and high TA fill water.

[Rangeball]

I've been lowering my TA for some time now, finally down to 120-30 from 180. Our area has high TA in our municipal water supply (must be something in the treatment as the city pulls their supply from the same aquifer my dad's sand point taps and his TA is 80), over 300 the last time I tested it last year. I don't have to top of much during the summer, but getting started in the spring usually elevates my TA.

I want to add borates, and thought I should probably get my TA down to 80 before doing so as I understand PH and TA stay much more stable with borates. I had also assumed this would be a good idea since my fill water has high TA and future TA reductions could be more difficult.

Am I on the right path? In my situation, how low would you go with TA before adding borates? As slow a job as it is currently, I was hoping to get the borates in asap before it gets really hot but don't want to make my life more difficult down the road, especially since I now TA is something I'll be continually trying to lower each spring.

 

[JasonLion]

Yes, you are doing well.

 

[Rangeball]

Thanks Jason. I've been taking advantage of rain aeration, and have a pool party coming up which I'll drop PH back to 7 right before to put everyone to work without them knowing it

Once borates are added, with high TA fill water can I still expect to get the PH stability borates provide? With borates in the water will it be more difficult to lower TA down the road when I have to add fill water?

 

[JasonLion]

High TA fill water will be just like adding baking soda, it will raise the TA, even with borates in the water.

Lowering TA with borates in the water isn't dramatically different, just a little slower and a little trickier to figure out amounts of acid (only chem geek's spreadsheet, a little complex for novices, does PH change calculations that correctly account for borates, though you can use an acid demand test if you have one).

 

[Rangeball]

Thanks.

 

[mas985]

I tried borates last year and I also have high TA fill water as well and could not keep my TA down low enough to show any benefit from the PH stability of the borates. So my acid dosage frequency did not change much with the borates. I would be interested if you fair any better but you may find that evaporation and high TA fill water makes it difficult to keep your TA down to a level where borates help with PH stability.

In addition, I have high CH fill water and so I end up replacing quite a bit of water each year to keep the CH down so my conclusion was that it really didn't pay for me to bother with borates.

 

[Rangeball]

Thanks.

My main purpose for the borates was algae prevention and reduced chlorine consumption. Stable PH would be a bonus.

So since it won't really matter in regards to PH, do you think I should go ahead and add borates with my current TA level of 125?

 

[mas985]

If the primary purpose is for algae prevention, then you might give it a try. Given the title, I had wrongly assumed that you were after PH stability.

I too had thought that borates might help with chlorine consumption and I could turn down my SWG but again I was disappointed and found that my chlorine consumption was about the same with and without borates. However, each pool has unique conditions so you can't really go by that. I have very heavy UV load on the pool even with a CYA of 80 so I suspect that most of my chlorine consumption is related to that instead of organic load although the trees around the pool do dump a lot of pollen and leaves in the pool.