How Often Do You Adjust Your Ph

[ana]

Even when we don't use our hot tub I still have to ajust the ph .I have to add 2 0z of borax every 3 days.

Ph 7.7 after the borax.

3 days later PH 7.2

Add more borax... PH 7.7

3 days later PH 7.2

Is it normal?

[chem geek]

Since your pH seems to be dropping and you are needing to add borax to raise it, this means you are using something acidic in your spa. Are you using bromine tabs and shocking with non-chlorine shock (MPS)? Both are net acidic. You can increase your TA level if it's low and that can help.

[ana]

We started the tub with the frog floater .After about 4 weeeks switch to 3 step bromine. ( did not drain)

Tub is being used in an average of 1 1/2 hours or less per week.

I did use the non clorine shock 2 or 3 times after the switch but in the last 8 weeks used clorax 2 times.

Have used baking soda few times when the TA was 80, in hopes that the PH will even out.

I do areate on occasion when PH is at 7.2 but that is just a temporary fix.

TA 100

CH 275

B 5-7 ( most of the time, sometime 10)

The tub is inside the sunroom. I was hopping I can wait few more weeks for the weather to warm up then drain and start over .

We're on well water with water softner.

Was just concerned of any ( ?) negative effects when using too much borax . Chemistry major i'm not!

Been using a OTO tester .I did buy a Taylor kit but got the K 2006 when trying to switch to chlorine method , then find out can not go from bromine to chlorine.( past post)

When using the Taylor k 2006 to test bromine, the water turned pink then clear. Added 2 more dips turned to pink then immediately start adding the R-0871 ( if I wait any time at all the water clears up)

I had to add 15 drops for the water to go clear .

Is my bromine level 33 ?

If I wait any time at all after adding 2 or even 4 dips , the water goes clear.

I added 6 dips of the R-0870 just to see what happens, the water was almost red then after few more swirls, hot pink. Added 14 drops of R 0871, water turned purple then a lavender- blue and stayed like that after 6 more drops.

I have the bromine floater out for the moment . Should I add some peroxide , then try to keep the bromine level low just to see what happens?

Hope you can help

Thank you very much.

[chem geek]

Mmmm... it does sound like the bromine level is so high that it is bleaching out the DPD powder. Are you using a 10 ml water sample? If so, then each drop is a little more than 1.1 ppm bromine so 15 drops would be about 17 ppm (with chlorine, each drop is 0.5 ppm with the 10 ml sample size and 0.2 ppm with the 25 ml sample size).

Yes, why don't you use some hydrogen peroxide to lower the bromine to a more normal level just to eliminate that as an issue. It takes roughly the same volume of 3% hydrogen peroxide to neutralize and equal amount of 6% bleach. About 7 fluid ounces of 3% hydrogen peroxide will neutralize around 10 ppm FC or 22.5 ppm bromine in a 350 gallon spa. Why don't you use half that amount to start with and see if you get a better bromine reading that doesn't bleach out in the test so quickly.

As for the pH, when you are using bleach the pH really shouldn't be dropping like that. Maybe your bromine tab floater is set way too high and that combined with the use of MPS were making the pH drop. If you are adding oxidizer (bleach or MPS) after your soak, then the floater only needs to be set to a low setting to maintain bromine levels in between soaks, assuming you are soaking less then 3 times a week. If you are soaking every day or two, you probably don't need the floater at all since what you add after your soak should carry you through to your next soak.

[GTATubber]

Is this in any way related to alkalinity? If alkalinity is out of whack, then the ph can wander easier, right? I know you can move alkalinity one way with an additive, but the other way requires a spa refill - I need to learn more about this too. There are products on the market that stabilize ph by stabilizing alkalinity. btw I have just heard of a new product that claims to almost reduce the need for chlorine or bromine (I have heard that before with silver stuff, ozonators and uv treatments etc - none of which works to eliminate the need for bromine or chlorine - but this new stuff looks promising, so will create a new post if the testing results are positive).

[ana]

Chem Geek, thank you for your help.

Bromine floater out for 9 hours, and I added 1/2 oz peroxide.No bromine reading with OTO tester ( maybe a hint of color)

Using the Taylor kit ( 25 ml.) , 2 dips of DPD powder water = pink, after 3 drops ( R-871 ) water is clear. B=6.7 ( right?)

ph 7.2

I keep the bromine floater in all the time , opened between 2.5 and 3.5 depending on OTO tester reading

I bought 3.75 Lb bromine tablets 7 weeks ago and they are almost gone, only 9 tablets left. Is that an indication that I have been keeping the bromine level too high?

If so, any negative impact except maybe that the bumps my husband is complaining about, are not flea bites after all.( dogs are not scratching)

This also explains the white powder settled in the creases/stiching of the tub cover.

Again, many thanks for your help

Ana

[chem geek]

It does sound like your bromine use rate was too high. Do you have an ozonator in your spa? If so, then it will produce bromine from the bromide (spent/used bromine). So try setting the bromine feeder lower so that your bromine reading doesn't get so high.