Spa contaminated?

[Ramla]

Hi everyone,

I recently converted the sanitizer in my spa from bromine to chlorine. I was getting bromine readings but didn't feel the spa looked very sparkly and clear. Once I switched to chlorine, I realized there might be a problem. We cannot hold FC at all. I followed the "shocking" process outlined in pool school (which worked for our pool) but it is not working for the spa.

1. Is there a different process?
2. Does converting from bromine to chlorine have any bearing on our ability to hold FC?
3. I read somewhere about decontaminating the spa. Is this something I should try? If so, how?

Thanks!

Ramla

 

[Ramla]

Oh, I should add that our ph is way over 8.1. I added some ph down this morning but am not sure if that does anything for the chlorine.

 

[UnderWaterVanya]

How were you adding the bromine? If you added it using the tabs then you actually have a bromine spa still - adding the chlorine just reactivates the existing bromides (?) and turns them back into active bromine.

But that shouldn't explain why you can't hold the levels - I think both are measured with the same tests.

Hopefully you'll have someone chime in with more specific spa / bromine knowledge. In the meantime you might try searching bromine here - there's a bunch of detailed info.

 

[chem geek]

I assume you completely changed the water. Otherwise, you've still got a bromine spa.

With chlorine, you need to add it after every soak and if you don't soak every day or two then you need to add it in between soaks as well. Unlike bromine coming out of the tabs on a regular basis, chlorine gets used up and you have to replenish it.

You may have just gotten behind in dosing, but shocking should hold the chlorine at some point. If you are adding it and it is getting consumed quickly, then it does sound like you may need to decontaminate. I suggest you use Spa System Flush and then superchlorinate (both using the water you've got now) and then drain and refill. At that point, you should be in good shape starting out fresh.