Water Cloudy

[sehaasch]

My 260 gallon hot tub has been great for the past 2 months. Water clear, chemical levels good. Lately, the temp has been going up to 108 even though I have it set at 80. Dealer is coming out to look at that. Now the water is clouding up. pH is 8.0, TA went from light blue to yellow when I tested it using the Taylor K 2006. Normally it goes from green to red. But the blue/yellow color change happened at 50ppm. CYA is 45ppm, free Chlorine is 18ppm. When I tried measuring CH and added 5 drops of R-0011L, it turned a very faint lavender and then to clear when I swirled it. I added 30 drops of R-0012 but no color change. Please tell me what's going on! Is it due to the high temp?


260 gallons, outdoor spa. Cartridge filter. No ozonator. 2 people use it 45 minutes once a week on average.

 

[chem geek]

As noted in the Potential Interferences for the Taylor K-2006 test kit:

High halogen level may change indicator reaction from green/red to blue/yellow; to prevent, add thiosulfate prior to testing.

So you can either add more R-0007 thiosulfate chlorine neutralizer drops or you can just look at the transition from blue to yellow since that is still a valid transition in the right place or you can wait until your chlorine level is lower.

The problems you are having are a combination of high FC and high temperature since the higher temperature has a higher active chlorine level at the same FC/CYA ratio. In other words, your chlorine level is too strong and is bleaching out one of the two dyes used in the TA test. What you are seeing is Bromocresol green that goes from blue at pH 5.4 or above to yellow at pH 3.8 or below. Your high active chlorine level bleached out the Methyl red that goes from yellow at pH 6.2 or above to red at pH 4.4 or below. Blue+Yellow looks green while Yellow+Red looks red when the test is done at normal chlorine levels.

It sounds like you are also bleaching out your CH indicator dye as well. I suggest waiting to test when the chlorine level is lower and let the sample get down closer to room temperature as well. I don't know why you have your chlorine so high unless you just dosed right after a soak, but that's not a good time to do testing. The best time to test is just before your soak when levels will be at their lowest for chlorine.

 

[sehaasch]

Actually I'm using Bromine not chlorine. Should I not bother testing for FC in that case? When I tested the Bromine levels, the color was burnt orange. My pH was dark lavender. Neither of those colors are on their respective charts. Does that mean those levels are super high? What numbers do I plug into pool math in that case?

 

[chem geek]

Oh, sorry I misunderstood. Well your bromine levels are too high. Burnt orange in the OTO test is too high for either chlorine or bromine. You should only have your bromine level in the 2-4 ppm range and certainly no need to go above 8 ppm (this is roughly equivalent to 1-2 ppm FC and not above 4 ppm FC). The only time you go higher is if there is a high bather load and you are dosing an oxidizer after a soak, usually without an ozonator.

If you've been adding oxidizer, stop for a bit. If you have bromine tabs in a feeder, crank down the feeder (or take it out for a short while if you have an ozonator). Let the bromine level come down to a level where you can read it on your test kit.

 

[sehaasch]

Is my pH high because my Bromine is high? Should I be adding any Muratic acid to lower it?

 

[chem geek]

The pH test may not be valid and can report falsely high when chlorine or bromine levels are high so I'd wait on the pH adjustment until after your bromine level gets lower, at least below 22 ppm Bromine (equivalent to 10 ppm FC). Basically get it to the deep yellow shown in the comparator in your kit, not burnt orange.

 

[sehaasch]

Is there anything else I can do to lower my bromine besides cranking down the feeder and waiting?

 

[chem geek]

Exposing the water to sunlight would degrade the bromine faster. You could use a chlorine/bromine reducer (usually sodium thiosulfate). Hydrogen peroxide won't work to lower bromine the way it does with chlorine.