The Great Tetraborate Experiment!

[waterbear]

I have been toying with the idea of adding borax to 50 ppm to see exactly what effect, if any, it would have on stabilizing pH. My borate test strips arrived last night so today I tested my water:
FC 5 ppm
CC 0 ppm
pH 7.6
TA 120 ppm (before stabilizer correction)
TA 97 ppm (after stabilizer correction)
CH 220 ppm
CYA 70 ppm
Salt 3500 ppm (used the readout on my Aqualogic which is usually about 100 ppm high so I am estimating about 3400 ppm which is where I was last Friday when I tested it)
Borates 15 ppm (measured with AquaCheck borate test strip. I have used Borax in the past to raise pH)

Today I added 1 box (4 lbs, 12 oz.) 20 mule team and 1 pt muriatic acid to offest the pH rise. (might have to add more acid. I am being conservative, based on the recommendations for Proteam Supreme)
I will test the water in a few hours for pH, TA, and borates.
According to Bleachcalc this amount of borax should raise my pool to 50 ppm but the dosing chart for Proteam Supreme requires a lot more, and the pentahydrate uses less by weight than the decahydrate (20 mule team).

I have been conversing with chem geek (Richard) about the dosing and these discrepancies. The aquacheck test strips are designed for testing Proteam Supreme. We shall see what the outcome is.

My main purpose in this experiment is to see if I get less pH rise with my SWG by adding the tetraborates. (or a slower pH rise). Currently it takes a little over 2 weeks for my pH to hit 7.6 from 7.2. I add 1 1/2 pts. acid every three weeks which lowers me back down to 7.2. I want to see if the borates will hep keep the pH more stable as claimed. Many of the SWG monthly mixes contain tetraborates supposedly for this reason along with boric acid to offset the high ph...adding muriactic acid will form boric acid in the water so this just eliminates that step. I know NaturalChemisty's Salt Water Magic contains the tetraborates and I will bet that Mineral Springs by Bioguard does also.

I will post my results in this thread as they become available. This might turn out to be useful info or a bunch of junk....don't really know yet.

[Rangeball]

I have never used borax and have a constantly creeping PH. Will be very interesting to follow along.

[waterbear]

Just checked my water and borates hadn't moved...still reading 15 ppm. If the proteam dosing chart is the correct one then I only added about another 6 ppm which won't show up on the test strips.
pH was off the scale. Added another quart of acid....in line with Proteam recommendations (and my acid demand test in my Taylor kit) so I will wait a while and retest. Gotta buy some more borax also.
So far this looks like what Richard and I expected and might point to a dosing error in BleachCalc.

[waterbear]

ok, tested borates and pH.....borates still reading 15 ppm and pH is at 7.6.....so 1 box of borax takes about 1 1/2 qts (48 oz) acid to neutalize the high pH. This is exactly in line with the Proteam dosing which says 10 oz. acid per pound. I put in 4.75 lbs (contents of one box) and it took 48 oz acid to bring the pH back to 7.6.

After I took the readings above I added 2 more boxes and a half gallon of acid. This was about 45 minutes ago and I just retested
Borates are now reading about 40 ppm (test strip color is right between the 30 and 50 ppm reading) and this is in line with the Proteam dosing and taking the weight difference needed for borax vs. supreme (.75 by weight of pentahydrate needed to achive the same level as the decahydrate.) the three boxes I put in (14.24 lbs) is pretty much the same as 10 lbs. of pentahydrate which will give me a ppm increase of about 23-24 ppm for my pool. Since I started with a base reading of about 15 ppm and am now reading about 40 ppm this is all in line.

The pH is testing at 7.5.

It's getting dark now so I will let the pool circulate overnight and continue tomorrow. My goal is to reach about 50 ppm borates. I figure it should take me about 1 1/2 to 2 boxes more to do it and maybe another 2-3 qts. of acid.

[waterbear]

restested my water this morning
FC 5 ppm (no change)
CC 0 ppm (no change)
pH 7.5 (no change)
TA 120 ppm (before stabilizer correction) (no change)
TA 97 ppm (after stabilizer correction) (no change)
CH 220 ppm (no change)
CYA 70 ppm (no change)
Salt 3600 ppm (It is hotter today, the pool water is at 92 degrees so this might be the reason for the higher salt reading...once again using the display on the Aqualogic)
Borates about 40 ppm (measured with AquaCheck borate test strip) (no change)


I added 2 more boxes of borax and 1 quart acid.

Restested pH and borates
pH is off the scale so I added another quart of acid and will retest in a bit.
Borates reading a bit higher than 50 ppm but not as high as 80 ppm. I guess 1 and 1/2 boxes would have been perfect. Once I get the pH corrected I am going to turn on the spllover and dump the spa water into the pool. I will let the system circulate for several hours and then recheck the borates. It might be just enought dilution to get me right on the 50 ppm mark!

[Rangeball]

Evan, are the borates supposed to stabilize PH even if alk is high?