FC dropping quickly during day, not at night
- Thread starter scottfy99
- Start date
2 containers, so 4 lbs total This was the third week of April when I opened. I had issues with pink mold for four or five years. Actually went through a liner change and still had issues. I believe now after reading some of the forum that my CYA was too high and chlorine was not effective. I considered at one point a change to salt, but put a UV light in instead. That wasn't a very smart move on my part.
Ok, so you added about 10 ppm of sodium bromide. That is almost certainly the root of your problem. Bromine is not protected from the sun by CYA, so it burns off quickly and as it does chlorine oxidizes the bromide quickly back to bromine so the process just continues until the sun goes away or the bromine disappears. Even just a couple ppm of bromide can cause this and the only way to remove bromide is to remove the water. Evaporation does nothing, you must dump water and replace it.
Quite a treat, isn't it :-?
Quite a treat, isn't it :-?
You would think Pink Treat would warn people about that. So, even draining to the bottom step and refilling four times doesn't help?
Or just do not put chemicals into your pool that you are unsure what they actually contain ... the basis of TFPC.
If you added 10ppm prior to drain and refills, assuming that you replaced 50% each time, after 4 drains it should be down to:
5 > 2.5 > 1.25 > 0.625ppm
(Unless Donldson accounted for the drains).
If you added 10ppm prior to drain and refills, assuming that you replaced 50% each time, after 4 drains it should be down to:
5 > 2.5 > 1.25 > 0.625ppm
(Unless Donldson accounted for the drains).
Pool chemical companies aren't in the business of telling people not to use their products. Tablet manufacturers don't warn about CYA buildup. Algaecide manufacturers don't warn about staining. Don't even get me started on what ionizer salespeople don't tell you...
Your CYA dropped from 100 to 30 during your drains, so your bromide level would have dropped from 10 to 3 from those same drains. It is just going to take more to bring it down, but you will have to replenish your CYA after you do. I don't know at what point it will stop being a problem, you will just have to do it and see how much it helps. Sorry, I really wish I had an easier answer for you.
Your CYA dropped from 100 to 30 during your drains, so your bromide level would have dropped from 10 to 3 from those same drains. It is just going to take more to bring it down, but you will have to replenish your CYA after you do. I don't know at what point it will stop being a problem, you will just have to do it and see how much it helps. Sorry, I really wish I had an easier answer for you.
I just tested.
FC 0
CC 0
PH 7.4
TA 90
CYA 40
CH 160
The UV is on at night and FC doesn't lower at that time. I believe it is connected to sunlight. Will bromine eventually fade? If I keep draining and refilling the pool will stay cold and won't be used. I usually close it mid-October.
FC 0
CC 0
PH 7.4
TA 90
CYA 40
CH 160
The UV is on at night and FC doesn't lower at that time. I believe it is connected to sunlight. Will bromine eventually fade? If I keep draining and refilling the pool will stay cold and won't be used. I usually close it mid-October.
I would take the uv out of the equation to reduce the complexity of the situation.
I would try to maintain fc at a minimum of 15% of CYA for a week and increase CYA to 60 ppm.
Your current level at 0 is allowing algae to grow.
It might be bromine related but your multiple drains and refills should have reduced the bromide quite a bit.
I would try to maintain fc at a minimum of 15% of CYA for a week and increase CYA to 60 ppm.
Your current level at 0 is allowing algae to grow.
It might be bromine related but your multiple drains and refills should have reduced the bromide quite a bit.
I will try that. I always pass the OCLT, but when I'm at work is when it falls and impossible to maintain during the day. Should I get the FC up to 9 every night? Saturday I'll be able to test during the day and see how quickly it drops. Thanks for everyone's help. I've made some bad decisions in treatment for a few years.
Bromide is a salt, it isn't really going away without being physically removed. It's up to you how you want to proceed, if you can find a way for your FC to not drop to zero then you can try to keep it going through to closing.
Most of us wouldn't be here if we couldn't say the same
If chlorine converts "used up" bromide to free bromide, it sounds like a vicious cycle. Would going a few days without chlorine help get rid of the bromide since it won't be coverted? I understand the algae issue, but if it would get rid of bromide I could take care of algae later. Thanks
Like most problems in life, sodium bromide does not just leave a pool if you ignore it.
I have about a month of pool weather left for this year. I'm going to try to get by and then drain 3 or 4 times again before closing. I have about 10-15 lbs of chlorine tablets left. I wasn't going to use them, but I also thought I was finished with draining and refilling. Would it be okay to use the rest of that since my CYA will lower when I drain and refill before closing? Would they cause any extra issue with the bromine? Thank you.
rllackey28
Well-known member
Side question. What app are you talking about? Viewing this thread through Tapatalk but I know about the page on TFP that has the chemistry comps. Is that what you are talking about? Would like a good reliable phone app so asking. Thanks.
- Jan 4, 2016
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rllackey28
Well-known member
It works great. Most of the time my results are equal to what is projected in the app if I add the suggested quantity.
How old is your taylor kit? Where do you keep it.
I recently found out that my kit was giving me erroneous results since it was expired.
I recently found out that my kit was giving me erroneous results since it was expired.