Felt I had never seen a bromine level over 1 or 2 on test strip

[w9oh]

Re: How do I use Bromine in my spa (or pool)?

350 gallon hot tub with new ozonator. tub recirculation and ozoneation is constant using small recirc pump. ozoneator is fairly high output. Had bad odor problem last year.
Seem to be fighting an odor problem.

I cleaned tub with chlorine-pumped out cleaning and flush water along with residue rv antifreeze, then filled it and added about two quarts liquid chlorine and circulated for a day. Cleaning included the cover interior with pool chlorine-looks good.
Dumped chlorine water and then refilled with new city water and put in a new filter.
Then added 2 oz of Sodium Bromide or mine, adjusted the ph using muratic acid and all was well. Heated to 104F. Put a floater in with one tablet. Looks like dissolving about 1 tab weekly. Got the TA to about 80. Then a day or two later, tub has an odor so I added a cup of pool chlorine. Maybe a little more than needed? Now got a strong chlorine odor along with a musty smell. Bromine test was off chart strip and ph went high. Turned on air blower for about two hours to help with ph and try to lower br/ch levels. Ph was then too low so added some ph plus for pools and got it in range. Aerated more with blower and ch/br came to a little under 9. Still having various odor problems. ph went low so adjust with muratic to 7.4 or so. Fill was about 5 days ago and used tub three times, one person. Presently have slight musty odor but bromine/chorine now tests low?????? In one day it went from 10ppm ch/br to near 0.

Last year used nonchlorine shock and thought the order might be coming from the sulfur based additive-is that possible?

Question
1. What br level to shoot for with ozone? What ch level to shoot for with ozone if I decide to change due to odor.
2. Can i use test strips to measure low br levels???
3. The odor I get is a foul, musty odor. Last year, my swim trunks had a permanent odor. Any idea what I am doing wrong? I thought that the bromine system had less odor but I am finding an odor.
4. Tub manufacturer suggests since tub has ozone that you float one tablet of Br per week, sanitize with PSul weekly.
5. What am i doing wrong.

Had a number of pools and can't believe this little hot tub is giving me such problems?????????
Richard

 

[chem geek]

Re: How do I use Bromine in my spa (or pool)?

Welcome to TFP!

Your test strips may be bleaching out at high bromine levels. You should first get yourself a proper test kit. If you are going to be sticking with bromine, then get the Taylor K-2106 kit; otherwise you can get the Taylor K-2006 (you can measure bromine with that as well, but you would convert units).

I suspect that your bromine level is simply too high and that is what you are smelling. You want to target 2-4 ppm Total Bromine before your soak as that will reduce the smell. You might need to add an oxidizer such as chlorine after your soak, but if your ozonator is working then that shouldn't be necessary. Because your ozonator is on so frequently and is presumably strong, it may be making too much bromine from the bromide bank. You may not need to use any bromine in the feeder at all and even then if there's too much bromine you may need to figure out how to turn off the ozonator part of the time (perhaps having the circulation pump on a cycle instead of always on).

 

[w9oh]

So b4 I got ur post, I thought about it and felt I had never seen a bromine level over 1 or 2 on test strip, last year also. That color is very hard to detect. So thought I would run the bromine up to a level easily detected. I added about a 3/4 bromine disk, crushed. Adjusted ph again down with HCl. Funny thing about the muratic, when added it turned a yellow/orange color in the area added, then cleared. Odor seems less now. Some odor when cover lifted but seems to dissipate after maybe a minute of blower. Some odor off cover-maybe from gas.

Strip says ph 6.9, bromine 9, Hardness 500, alk 80.

I then got your post and thought, oh no, I have added more bromine so... I grabbed a spa water sample and diulted it with 80% tap water. Using test strips again (thats all I have) the diluted sample was about 2 ppm and the full strength was about 9. Guess I ran it up to about 9 or so and the strip isn't being bleached. Maybe the bromine has been too low the entire time???

Not real sure about the 'high output' description but the ozonator is a Prozone PZ1 rated at 800 gallon spa. I could put the ozonator on a timer and leave the small filter pump run. The pump runs through the heater and maintains temperature.

So bottom line, now I do not know how to maintain this spa. I would guess that I should try to keep bromine around 3-4, ph in 7.2-7.6 range, alk 80 or little higher. I should add bromine to float feeder weekly if that maintains a desired concentration and super sanitize or shock about weekly (assuming spa usage of one person, 4 -45 minute soaks weekly). Can use either 5 oz liquid pool chlorine or 2 tablespoons of persulfate compound. Have I got it ok??

I wonder if last year the bromine level was always very low and when I added persulfate compound-maybe it built up and caused the terrible odor?? The odor at times was stronger and it seemed the addition of persulfate resulted in more odor the next day I was using more than two tablespoons, maybe double that weekly.