Hi, question regarding how to reduce excessive ph after adding Borates. I used the calculator to determine the appropriate mix of 20 mule team borax and muratic acid to add 25 ppm borates for my 375 gallon spa. I started with balanced water (7.6 per my calibrated ph meter). I added borax first, then muratic acid. Perhaps I should have reversed the order. I planned to add the other 25 ppm borates later as I read it's best to do it in smaller doses. After turning on the jets for 15 minutes and waiting a couple hours I noticed my ph increased to 8.6! Should I just wait a bit longer to see if the ph stabilizes lower? Or should I add more muratic acid or some other ph reducer to get the ph back down before adding more borates?
Lowering ph after adding Borax
- Thread starter tomdav
- Start date
- Jun 12, 2011
- 3,767
- Pool Size
- 19500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pureline Crystal Pure 60,000
Give it about an hour and retest the pH. You may have been off in your calculations or your estimate of the pool volume.
I'm assuming the manufacturer spec for spa volume is correct. That said, miscalculating volume should only impact the ppm of borates added (ratio of borax to muratic acid shouldn't vary by volume). I added 10.5 oz borax and 5 fl. oz muratic acid.
ph hasn't gone down so I guess I'll just add muratic acid to lower it..
ph hasn't gone down so I guess I'll just add muratic acid to lower it..
Borates will always raise your pH. Yes, do the acid. Spas seem to over-react.... or rather humans seem to over-add. Watch it. Do no more borates for a few days.
spas over-react because a few mm of chemical adjusts things so quickly..
When we deal with pools, a few mm makes little difference. Spas, are running on 500gal . A mm of difference
is an actual ppm.
When we deal with pools, a few mm makes little difference. Spas, are running on 500gal . A mm of difference
is an actual ppm.
Well, mystery has been solved. It seems the muriatic acid I purchased at Lowes was diluted 50% to make it "safer". Gee half strength for the same price, thanks Lowes! Once I doubled the muriatic acid the PH is back in balance.
I have that same acid. It is less likely to fume and easier quantity to measure due to the half-strength. It also makes for a nearly 1:1 ratio of borax to acid (at least in metric).
I mix up two 5 gallon buckets of spa water: one with half the required acid, and another with half the required borax. I then slowly add those to the tub with the jets running alternating between buckets. Probably overkill, but keeps the pH from swinging too wildly.
Next time I’ll just order granular boric acid from Duda-Diesel.