I just found out my pool used to be a bromine pool

[Jordy Verrill]

We bought our house a year ago and I started taking over the pool using he TFP method, keeping my FC/CYA levels correct all summer long and our pool being beautiful. Then today I discovered that the previous owners had used Bromine, not Chlorine, and googling led me to discover that Bromine always stays in the pool and you can't change it without draining, which I can't do right now. I am in the middle of my season opening SLAM, I've been doing everything assuming that my pool is chlorine, spent all last summer with no problems assuming my pool was chlorine... what do I do now? Just keep going with it? I know Bromine eventually burns off, and I have been backwashing/vacuuming to waste a alot this spring.

I'm lost/confused/depressed/anxiety filled about this new discovery. I'm seeking reassurance/help.

 

[JoyfulNoise]

We can help but it is likely to be a bromine pool for the foreseeable future.

Question - how was your FC last year? Did you notice your pool water losing FC a lot or having more than a 2-4ppm per day FC loss? Also, do you know what kind of bromine sources the previous owner was using? Was it tablets or did they just use sodium bromide to add the bromine to the pool? Any information you can dig up will help us help you.

Don't freak out, it's ok if there is bromine in there, it's just something you'll have to live with until you can afford to do a larger water exchange. Being in Ohio, if you can let rain water overflow your pool (or drain before it rains), the dilution will help a lot too. There is one upside to bromine - it tends to kill algae a little more effectively than chlorine because monobromamine is a better algaecide than monochloramine. It's one reason why United Chemical sells a brand of algaecide that is just sodium bromide crystals.

 

[JamesW]

Maybe consider getting a SWG. They produce consistent chlorine and can help make your pool more manageable.

 

[Jordy Verrill]

I did go through about 5-6 FC loss per day last year, but I chalked it up to low cya as I never got more than 30 on that test, and the constant barrage of leaves and mulberries in the water from a mulberry tree near the pool, which I had removed this winter. They used bromine tablets, that's how I found out about it... I found a half empty bucket of them in the back of the shed that I haven't really used since moving into the house. I asked the pool store they used, they were complete pool store people and the store knows the pool well, and I use the store now too for hardware and opening and closing since I'm not comfortable with doing that myself. Anyway, the store said yeah, they used bromine tabs because one of them were allergic to chlorine.

I'm planning on having the liner replaced next year, since it is 15 years old, so I only have to get through this summer with the bromine water. I guess my biggest concern is what should I be aiming for with my FC and CC tests? And do any of the other tests have to be adjusted? I used the Taylor 2006k test kit, do I have to multiply by 2.25 to get my bromine level? What should my bromine level even be? How do I know how much bromine is left in the pool? I do a lot of vacuuming to waste, especially last year with the blueberry situation. I know bromine isn't recommended here so I don't expect anyone to be an expert, I'm just hoping for a little guidance.

I'd like a swg eventually, but it's not going to happen this year. Too many home improvement projects already and my wallet is tapped out.

 

[JoyfulNoise]

A 4ppm/day loss is what would be considered in the high range of acceptable for a chlorine pool. Normally, bromine can not be stabilized against UV loss like chlorine does and so one expects to have a much more rapid loss of sanitizer when bromine is present in an outdoor pool. Unfortunately, there is no way to measure bromine separately from chlorine using any standard pool test kit; the DPD indicator in the K2006 reacts to both.

It's hard to know what your actual bromine levels are so you basically need to treat the pool like a bromine pool and use the bromine scale on your test kit. Because of the details of bromine chemistry and DPD, the test really should only be a measure of total bromine since both free bromine and combined bromines react with the dye in the first part of the test. I would not even bother adding the R-0003 as it is not really valid when bromine is present.

Also, the brominating tablets contain a chemical compound called DMH (dimethylhydantoin). DMH is used to help stabilize bromine against UV loss (although it does this poorly) and it helps to moderate the levels of hypobromous acid, the active sanitizing form of bromine. But again, DMH is not very good at it AND, like too much CYA, too much DMH can lead to over stabilization of the bromine levels and cause algae problems. Once again, there is no way to test for DMH in pool water so, without knowing how much was added, you're basically shooting in the dark.

I understand you're waiting for a liner change and so the best you can do at this point is to try to backwash and vacuum to waste as much as your wallet can afford and let mother nature help you out when it rains. If you can try to drain the pool and inch or two before a big rain storm and/or try to divert roof water from a gutter into your pool, you can help to dilute the bromine levels as much as possible. I wold also keep doing what you did last season and maybe bump up the sanitizer level so that you have at least 8 to 10 on the bromine scale. That should hopefully keep your pool water out of trouble.

Once you get your new liner and can refill with fresh water, you'll be a lot happier managing a chlorine pool...

 

[Jordy Verrill]

So 8 to 10 on the bromine scale would be in the 4 to 5 ish range on the FC test? That's around what I'm aiming for anyway after my SLAM is done.

Thanks for the help. We have a weird quarterly water bill cycle here, and the summer quarter water bill price is capped at the average water bill price from the rest of the year, so I have no problem adding water from my garden hose once I'm in my summer quarter in mid May. I don't have a drain in the bottom of my pool though so I would have to somehow pump the water out, which sounds like a pool store job, and then worry about my liner bubbling up or whatever problems come from emptying a pool. I will just wait until I get the new liner but vacuum to waste, or just dump water to waste, more often once I'm on that summer water bill if it helps with lowering the bromine.