Bromine testing?

[giulietta1]

I hope someone can help me! I've got my spa going now. I filled it last night and shocked it with the brominating concentrate (the stuff that has the dichlor in it). Since I have the Taylor FAS-DPD chlorine kit, I ordered a cheap test kit that purported to test chlorine, bromine, and pH. Well, its labeling says it tests bromine, but there are no instructions for bromine!

I seem to recall reading somewhere that you can use a chlorine test and then divide by 2.25 to get your bromine #'s. . . Do I have the right correction factor? Am I imagining things?

TIA for any help. . .

 

[Guest]

You want to MULTIPLY by 2.25 to get your bromine reading or you can just pretend that you are using chlorine and make adjustments as if you were testing chlorine. I know this works with OTO and DPD. You might need the special FAS-DPD test that Taylor has for bromine. With bromine you only test total bromine.

 

[giulietta1]

Yikes! Yes, I found that somewhere else, too! I was hoping it was a mistake. I'm not sure how I could have that much bromine in there--that would mean close to 30 ppm, based on this morning's test! Last night I put in the recommended startup shock dosage, which came to 10 t, which is 3 1/3 T, which is just under 1/4 cup. So that's what I added (of a "brominating concentrate" which has more dichlor than sodium bromide).

I just assumed the amount on the container would give me about 10 ppm. Maybe that wasn't the right assumption!!

Maybe I had a testing error. I will see what I get tonight.

 

[Guest]

I assume you are using a 1 step type of product that contains both sodium bromide and dichlor. Until enough bromide ions build up in the water from continued use you basically have a chlorine spa. Same thing happens when bromine tabs are used by themselves. This is why I like a separate sodium bromide additive (just sodium bromide and nothing else) added on each fill so you have the 'bromide bank' in the water from the start. This insures that you have a bromine system from the very first shocking with chlorine (or other oxidizer).

 

[giulietta1]

Yes, it's the one-step product. I bought what the pool store had. :? I will order some just-plain sodium bromide when this stuff runs low.

So does that mean I should actually run the chlorine test on the spa for the first few days after start-up, if I'm using this 1-step product?