Adding Boric Acid

Methuselah

Well-known member
May 9, 2022
470
Alabama
So first, thanks to all for all the great information in this Spas and Hot Tubs forum - tons of great questions and the answers have been invaluable!

My new hot tub's running now about 7 weeks and I'm finally feeling like I'm learning where TA and PH want to be. Bleach additions initially drove PH down, but I've lowered the TA to about 60 with the granuals from the starter kit at first, then Muratic acid and it's been stable at 7.5. It had the beginnings of foaming, so with a few trips to the pool store for free testing I took CH from 105 to what should be 135 and that's helped.

Now I want to add Boric Acid and the pool math page seemed to agree proportionately to the post here:


or 20'ish ounces for 515 gallons. I bought powder, not the granuals in the form of Hot Shot "1 lb. MaxAttrax Roach Killing Powder with Boric Acid" ( label: 99% Orthoboric acid). Again with my new word for the day, proportionately, about 39 ppm.

Here's my question --- for granuals they are cast into the water (at least in a pool), but no recommendation for powder, other than Hot Shot saying not to snort it. Do I need to add it to a bucket of water first, or powder first water second? Does it dissolve better if the water is hot?
 
For powdered add it to a bucket of hot tub water- i mix it with a paint stick. I Also run it through a mesh strainer (pool skim net) while pouring it in the tub - the powdered stuff globs up & just wants to float on top of the water. Granular is much easier to deal with.
* For future reference u are not supposed to use the roach stuff - i have in the past with no ill effects but it’s really not the purest stuff - if it’s blue definitely don’t use it.
For the future order some granular boric acid from duda diesel- it doesn’t take much for a hot tub so one container should last for quite some time.
 
Link "Further Reading" looked familiar, either read it before or just similarities to "Borates - Why and How".

After posting, another $3 word popped into my head (solubility) and I googled it. One had a chart indicating water would suspend a higher percentage if cold, and some mixtures with water for insect control put a cup into one gallon.

So started with dumping the pound (was 16.1 oz, bravo Hot Shot) into bucket and adding 1.5 gallons. Nope, brought it up to about 2.5-3 and 99% was dissolved. I let the undissolved stay in the bucket.

BTW, thanks for tip on color, it was white. Water looks good.

I did research pricing for the Boric Acid including dudadiesel.com and the $3/# at Home Depot was best price for a small quantity that I could put hands on quickly. I see now your reference indicates it could be 40% other stuff without disclosure ... live and learn. There's a 800# on the MSDS for more info, maybe I'll ask them and report back.

Thanks for posting/responding :)
 
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I once ordered powdered to put in my pool because it was a little cheaper….
big mistake! It was a nightmare! Trying to dissolve 60+ #s of it a solo cup at a time was horrible. Never again. It took forever.
 
Just got off the phone with Corina at Hot Shot. The 1% is "inert" and the 99% is 100% Boric Acid, no mix or lure added - just Boric Acid. I reckon I got lucky and it would not surprise me if this were subject to change however I'm going to continue to use that product for future fills as $3 per # seems quite reasonable. They have an MSDS (well, SDS - safety data sheet) online so hopefully if things change they will amend the data sheet.

Still I'm glad I checked, better safe than sorry! Let me add, there was some reference to some of these bug poison products being blue - I'd agree it seems those should be avoided.
 
Been reading (again) on adding borites while stuck at home quarantined for covid, Paxlovid seems to stop it in its tracks...

In questions below product on Lowes website manufacturer answered the 1% was Talcum powder. So for the one pound container it's about 2.5 ppm. MSDS on Talcum powder shows some quartz and metals content.

Looks somewhat benign? Anyway, haven't added again this refil, but if I use up what I bought (2# left) I'm thinking the filter may remove it?

FWIW I didn't save much over the preferred source duda diesel at $3/pound, but it was available without having to wait on mail order. Since I only have 2# left I might just order and give the hot shot to the kids (both just moved into "new" homes).

Is 20 mule teams borax also pure boric acid? I'm all in on local purchase especially if cost effective...
 
Is 20 mule teams borax also pure boric acid?
No it's Sodium tetraborate and will need you to add several rounds worth followed by MA corrections as it spikes the PH. The cheaper borax is offset by the pricey MA, plus your time.

Boric acid is the preferred addition. (Hydrogen borate)
 
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Buy a 9kg tub of Bioguard Optimizer Plus, which is 100% boric acid and pH neutral. The old Bioguard Optimizer (without the Plus) is tetraborate pentahydrate, which drastically increases pH and usually you need to counteract with acid.

If you ever need to increase pH, 20 Mule Team Borax is great for pH increasing, and adds a small amount of borates at the same time (see Effects of Adding Chemicals calculator at the bottom of PoolMath)
 
Buy a 9kg tub of Bioguard Optimizer Plus, which is 100% boric acid and pH neutral. The old Bioguard Optimizer (without the Plus) is tetraborate pentahydrate, which drastically increases pH and usually you need to counteract with acid.
I'm seeing the + as the same old STP.

Screenshot_20221108-142046_Chrome.jpg

And it's pricey per k/lb.
 

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The 1% Talcom stuff was $3.00 a pound. I think the recommend duda diesel stuff I looked up was slightly over that. I did say local though...

Also (off topic) found the 2 week ago factory sealed chlorinator lost potency quickly. Strange. It had sat indoors for about six months.
 
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