Arrrgh! Darn Chemicals

[brentp]

OK - been fighting a chemical issue since we installed our new SPA in Dec.  Have had to dump the water twice due to very cloudy water which I could not control.  Never had this bad of an issue in the 12 years with our old Hot Tub, . . . something has gone haywire.

Anyway, . . .  broke down and purchased a Taylor kit to try to get to the root cause.  We use a Bromine feeder and the system has a 24/7 circ pump with Ozone.  Have had to turn the feeder way up from where we use to use it in the old tub (just assuming tubs are different - this one needs more even though ~ same size).  After testing with Taylor, sanitizer is ok, Cal Hardness ok, TA low, PH High per the Taylor kit.  Compared with Test strips - readings all over the map, but both test strip types show PH is ok.

So, . . . add baking soda to increase TA, . . . good - it worked and is around 120ppm.  Only thing out of whack after this was the PH is still high per the taylor.  Tried to lower PH with dry acid, . . . but the only effect was it brought the TA back to a low level (PH still reads high).  I then built the TA back up with baking soda.

So, . . . I read that it is next to impossible to have high PH with bromine if the balance is ok.  Might get a false reading and that Bromine could effect the PH test so you may need to neutralize the sample.  OK, I tried 2, then 4 drops of R-009 (think that is the number - the stuff you start the TA test with) before the PH test - still high.  I also read that testing after use or with lots of injected air may result in a false high reading.  So, . . . I shut off the ozone system for 10 minutes and re-test - still high.

Color is deep red - almost with a bit of purple, which is off the high scale (8.0+).  I am clueless on where to go from here.  Given one of my test strips is reading PH around 7.6 - I am starting to think this truly might be a false reading.  I also tested my source water (well) just for kicks - reads 7.6.  So - this means that PH would have had to increased in a bromine system.

Any suggestions on more things to try?

[txwillie]

If you have somewhere you can take the water to get tested, do that. Leslie's pool supply (think they are just about everywhere) will do the analysis and give you a printout of just how much of what to add. FWIW, I use strips and find that my readings match an in-store anaylis every time.

[The_real_Clown_Shoes]

Bromine will raise the pH and lower the alkalinity over time.  It is a common issue people run into.  If you add a couple Tbs of bisulfate you should be right as rain again.

[Reese]

Bromine will raise the pH and lower the alkalinity over time.  It is a common issue people run into...

How does that work? :-?  I'm not a bromine user, but I thought bromine was low pH, and should bring down both TA and pH over time.  Seems like you are "defying the laws of physics, Captain" (actually chemistry )

[The_real_Clown_Shoes]

Can't remember exactly how it occurs, I just know that it does.  Through observation both residentially and commercially the pH in a bromine pool/spa will shoot sky-high if unchecked, while the alkalinity gets bottomed out with the tablets.

[txwillie]

back in the dark days when I used bromine, I was constantly adding baking soda to raise both TA and PH

txwillie

[The_real_Clown_Shoes]

The biggest determining factor is the source water.  I'm trying to remember exactly what the explanation is.  I'll do some digging and get back to you all about it tomorrow afternoon.

[brentp]

back in the dark days when I used bromine, I was constantly adding baking soda to raise both TA and PH

txwillie

Exactly - and is what I always needed to with my old SPA, . . . adding a bit to bring it back up - never being too high.  Now, PH is way out of whack on the high side according to Taylor test kit (but ok with 1 of 2 test strip I use), . . . hence my sense is this may be a false high reading, especially given the maroon/purplish color of the test.  This is one of the things the Taylor manual says to look out for.

Bromine will raise the pH and lower the alkalinity over time.  It is a common issue people run into.  If you add a couple Tbs of bisulfate you should be right as rain again.

Very interested in understanding this more.  From everything I can find - bromine should lower both PH and TA over time.  If you can dig up the info on the source water - that might give me something to look for.  FWIW - we did have our well disturbed harshly this summer for a pump replacement.  Disturbed a bunch of the iron sediment - we needed to bypass our iron filter for quite some time - but now, everything appears back to normal on the source water front.  PH = 7.6, TA = 60, and no iron (due to filter).

SPA Test Readings from last night (w/Taylor Kit):  Bromine = 1.5, PH 8.0+ (off scale), TA = 140, Cal Hardness = 125

I think it is now time to head to the SPA store and get my water tested there as suggested - just to understand what they are getting for results.

Anyway - thanks for the input - something sure is different with this new SPA.  I'm sure we will get to the bottom of it sooner or later.

Any other advice out there??

[hottubdan]

TA is high.  You need to knock it down.  Shoot for the low end of ok range.

What kind of bromine are you using?  I know of threee different formulas.

Do you use stain scale or metal control?  I am told by a chemical rep that many of those will raise TA.  

[The_real_Clown_Shoes]

How much air are you injecting into the spa?  If you have all your jets with all the air on, that can contribute to the high pH.

[mader]

I had the same issue with the taylor test kits.  I use the bromine tabs in a floater, have an ozonator as well.

Taylor test kit always shows that purple reading you describe...8+ ph.  My test strips, and I have tried multiple ones, all said PH was 7.5 or so.  Drove me nuts.  I stopped using the taylor kit, but I still don't know why I was getting false readings from it.  I tried adding thiosulfate drops, etc.

[brentp]

I had the same issue with the taylor test kits.  I use the bromine tabs in a floater, have an ozonator as well.

Taylor test kit always shows that purple reading you describe...8+ ph.  My test strips, and I have tried multiple ones, all said PH was 7.5 or so.  Drove me nuts.  I stopped using the taylor kit, but I still don't know why I was getting false readings from it.  I tried adding thiosulfate drops, etc.

Thanks, . . . guess I'm not the only one going (gone) crazy with this  


On the Bromine Tabs being used:  1-Bromo-3-chloro-5, 5-dimethylhydantoin 96%

On the Air - During use - lots of air.  But I tried testing in the morning to make sure this was not an issue.  Only air in the morning is from the circ pump injection of the ozone.

No metal control other that what is included in SeaKlear, . . . and I only add 1 oz every week or so on that.

Only other things every added to the water are Oxy-Spa shock,  ~ once a week, . . . and occasional fragrance during use.

Thanks for all the ideas - think I get a sample up to the local store this weekend just to see if PH high is real or a false high.  Then I can go from there.

[brentp]

Just wanted to give an update on where we are with this.

Went to the local pool supply store for a water test to see what was up.  Before I went, I ran the water through the taylor kit to see where we were at;

PH 8+, TA 120, Hardness 125

Pool store came back with;

PH 8, TA 107, Hardness 118, Slight copper (0.2), no other metals or any other tests that jumped out as issues.

So, . . . I can conclude that the Taylor kit is pretty close to accurate and have thrown away the one set of test strips that was reading PH at 7.6 - so much for thinking/hoping the PH reading might be a false high.  

Spent the better part of the day on Sunday working the PH down with bisulfate - adding a bit at a time and then correcting the TA to stay within range.  Finally got the PH to read ~7.4 on the last cycle.  But - this required what I thought was a significant amount of bisulfate added over the multiple cycles.  Thought I might be home free on this, but wanted to wait a day and see if it would hold.

Went home last night to test again after 24 hours - PH back up over 8 once again.  TA/Hardness both ok still.  Something with this SPA is out of whack.  I will just have to keep trying and looking for answers I guess.  

[Chad]

Brent,

Experiment with keeping your alk at different levels until your pH stabalizes for longer periods of time. Don't worry about how low or high you have to take it as long as your pH is in range and stabilized.

[brentp]

Thanks, . . . will add this to the list of experiments