Indoor pool w/bromine tabs changing...

[ramor]

Hi all,

This is my first post. I'm trying to weigh the "don't post a question that's already been answered" rule against the "don't hijack someone else's thread" rule, so please excuse me if I've come down on the wrong side of that.
No problem. Any time you even think it may be a hijack, start your own thread. Butterfly
My question is similar. We have an indoor pool, and we have always used Bromine tabs in a large in-line feeder, which only needed to be filled every 3-4 weeks. The first few years I did this myself, then life happened and we decided to outsource the maintenance. Now my wife has gotten into a fight with the pool company, so "we've" decided to take it back over ourselves (i.e. she has decided that I will do the maintenance).

However, in the intervening years, the pool company has replaced our old Bromine feeder with a new Biolabs TC-Series TC-25 TriChlor feeder. The feeder has all kinds of warnings about not using Chlorine or Bromine, risk of fire, use only Biolabs chemicals, etc.

I purchased a couple of 50-pound buckets of Bromine from an online store last year, and it *looks* like they have been using those in the TC-25 since they installed it, but I'm not sure. There's definitely no TriChlor tabs in our basement, so unless they've been bringing what they needed every month and not leaving any extra, they've probably been using the Bromine. Based on what I'm reading above, it sounds like it's actually fine to use the TC-25 for Bromine as long as it's *only* ever been used for Bromine. But you could have issues if you mix. Is that correct? Aside from the labels, I can't see much functional difference between our old feeder and this new one.

The fight has been going on for three months, so there's been nothing in the feeder since then. Not surprisingly, the water is now quite cloudy, and when I drop a DPD-1 tab into my crappy little test kit there is absolutely no color change at all to the water, so I believe FC (or is it FB?) is 0.

I've pulled the basket out of the feeder and rinsed it out with the hose. Do I dare just put in some Bromine and let it go? Obviously the right thing to do is call the pool company to see what they've been doing (my wife and I have always been at work when they come so we have no idea), but I'm not even sure we're on speaking terms at this point. If they were using TriChlor, would running water through the feeder for 2 months with no TriChlor tabs be enough to make it "safe" to switch the feeder to Bromine even if they were using TriChlor before?

Sorry I don't have full readings for the pool other than FC. I just ordered my TF-100 kit yesterday, so it should be here Friday, at which point I can post full readings. The pool is ~18,000 gallons, 12'x32' gunnite, with a Sta-rite Series 3 (S7M120) filter, Pentair Whisperflo pump, and Sta-rite SR200NA heater, if that helps. Every single one of those has been installed since we purchased the house 7 years ago - most in the last 4 years.

Thanks in advance for any advice for this newbie!

 

[JasonLion]

Welcome to TFP!

The feeder certainly could have been using bromine tablets. One way to check would be to measure the CYA level. If they were using trichlor you will have a measurable CYA level, and if they have been using bromine your CYA level should be zero. You never want to use two different chemicals in the same feeder, even after two months of being empty. The odds are good that it is cleaned out, but even a small amount of residue of the wrong chemical could cause an explosion.

I suggest putting a couple of bromine tabs in the skimmer and running the pump 24/7 for a little while, until you can measure the CYA level. Tabs in the skimmer are only alright when the pump is running 24/7. Running the pump extra will also help clean up the current cloudiness. I also suggest adding a small (96 oz) bottle of bleach (unscented no special features) to the pool, pour slowly in front of a return jet while the pump is running. That will help bring up the bromine level more quickly.

 

[ramor]

Great - thanks! I'll give that a try and let you know how it goes. I did get my TF-100 yesterday, so I should be able to take all the measurements today, and then again in a couple days after trying these options.

 

[ramor]

Ok - I did as JasonLion recommended - 2 bromine tabs in the skimmer, pump running 24x7, and a 96oz bottle of bleach in front of the return jet. After about 30 hours, the water is noticably clearer, which is great!

I took readings before doing any of that, using the TF-100. I got:

FC: 0
TC: 0
pH: 7.2
TA: 120
CH: 230

CYA I guess was not measurable? Was the water supposed to change color in the mixing bottle? It remained completely clear, so there was no amount I could put in the viewing tube that would obscure the black dot at the bottom.

I just did the quick test again tonight. pH moved up to 7.5, but FC still didn't seem to measure - the water remained completely clear, which is not what I expected. However, I ran the test again on my old test kit with a DPD-1 tab and got the same result.

Thank you very much for the help - I definitely seem to be back on the right track. What do you recommend for next steps?

 

[JasonLion]

No CYA means there hasn't been any Trichlor used, so you can use the tablet feeder with bromine tablets.

FC indicates the bromine level, which is currently zero. You want to keep bromine around 3 to 5, keeping in mind that bromine is 2.25 times the FC level, so you want FC to read between 1.5 and 2.5. You can add chlorine to raise the bromine level, since chlorine will reactivate the bromine bank.