Dealing with high ph source/mains water will muratic acid better than dry acid?

[Jcwminiadventures]

Hi
I'm after some advice on how to lower my ph levels in our vita prestige hot tub when dry acid doesn't seem to touch it.

Our main water ph is over 8 heading towards 8.4 before I start but Alkalinity isn't not high. We're in a particularly hard water area to.

Drained & refilled just over a week ago as cynuric acid levels were high & was due to be changed anyway.

Chlorine floater tablet dosed

Alk reading being maintained around 100

Tested with a Photometer & test strips

Tried many failed attempts with ph minus/dry acid to mostly no availl if I do get it down or wipe out as soon I re balance the alkalinity I get ph bounce. Just so frustrating when I can get everything else within recommended range minus the ph,
Can't be adding ph minus every other day!!

Would muratic acid work better & where do I buy in the uk/what strength etc? or any other suggestions welcome.

 

[dsmith99]

With the amount of aeration in a hot tub your alkalinity is a little high. With higher alkalinity aeration will rapidly increase PH. Use muratic acid to lower the PH down to 7.2 and alkalinity will also lower. Aeration will continue to drive PH upward and you can lower PH again until you get the alkalinity down to between 60-80. Somewhere around there you will likely find a point where PH becomes more stable.

Dry chlorine products like tablets add CYA at a rapid pace, in addition they are corrosive and should continually try to drive PH lower, it is common when they are used to actually have to increase PH regularly. I use dichlor/bleach to maintain my hot tub and it works very well. My PH has remained at a steady 7.6 for weeks and CYA decreases slightly over time. Dichlor is used at first to establish a CYA level as well as maintain the FC, then switch to bleach to maintain the FC without pushing the CYA up further. If I test and find CYA getting a little lower I just dose with dichlor for a day or two.

You really need a more accurate test method, test strips are time and again proven inaccurate. Electronic testing can be hit and miss as the equipment requires frequent calibration. TFP recommends either the TF100 or the Taylor K-2006 to accurately test both pools and spas. These contain all the other tests you need as well as an extremely accurate FAS/DPD chlorine test that also tests for combined chloramines.

How do I use Chlorine in my Spa (or pool)?)