Bromine pool forever? Please help!

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L

LD Stewart

0
Feb 14, 2017
5
Dallas, TX
This is my first post so please be kind! We remodeled our pool last summer so it was a new fill. I have a kiddo with eczema and decided to convert to a SWG about a month ago. The conversion got delayed about a week and in the interim I accidentally let the FC go to zero for about 2 days. I added liquid bleach to get the levels back up to 3ppm and started up the SWG and have maintained it around 3ppm ever since (CYA is 55). I have been fighting mustard algae this whole month. Water is clear but if I don't brush every day it starts forming on the walls again.

I made the mistake of going to the local Pinch a Penny for help who told me to add 12oz of Yellow Klear (sodium bromide) and 4lbs of shock for my 35,000 gallon pool. I specifically asked what would happen to the bromide in the pool and they assured me it would be used up in 24 hours. Not knowing any better, I did what they said. Of course the algae is gone, but do I now have a bromine pool forever? I am so furious that I didn't do my homework and that they told me it would be fine!

Readings before adding bromine:
FC 3.19ppm
TC 3.28PPM
pH 8.2
Hardness 264
Alkalinity 90
CYA 55
Copper/Iron 0

I added MA to bring the pH down to 7.6, 12oz of Yellow Klear, and 4lbs of calcium hypochlorite granular shock 2 days ago

Current FC and pH are 5ppm and 7.6

Outdoor 35,000 pebble pool in Texas - sunny. SWG has been off for the last 2 days.
 
So you’re looking at 2.5ppm bromine in the pool, it’s on the low side but not insignificant. The good news is you have an SWG that will constantly regenerate the bromide into bromine through oxidation. The other good news is that when bromide is oxidized, you get bromine AND bromates formed. The bromates are a stable, oxidized form of bromine that will no longer cause you any FC demand issues. However, the Pinch-A-Penny Guy is wrong, it will take longer than 24 hours as the bromate formation reaction is slow.

I suggest you follow TFP’s advice on how to eradicate mustard algae. You will be SLAM’ing the pool but it should be a short SLAM. The increased FC levels will also help to further oxidize the bromine to bromates and you should see any excess FC demand go away soon enough. If water is cheap you could also drain a little bit and refill to allow dilution to help you out.

Best not to listen to the pool store folks without checking TFP first. Most of time, 99% of the questions you need answers to can be found using the Search box.
 
Thank you so much! I am certainly done with them forever after this debacle. This isn't the first time they have told me something that was totally wrong, either.

The algae was very minimal and looks good so far. If it comes back I will SLAM it and clean behind the light fixture in case that is the issue.

Will I eventually be back to a chlorine pool if I just keep the chlorine levels stable with the SWG? I hate to think about draining this large of a pool!
 
Your pool will eventually get back to normal. You may see excessive FC demand in the short term. Typical daily FC loss should only be 2-4ppm/day. If you are experiencing higher than that, the bromine might be responsible or you could have algae starting (algae builds up in the water long before you can see it visually).

You should base your need to do a SLAM on overnight chlorine loss, not visual appearance. As we always say around here - clear water is not proof of clean water.
 
kimkats said:
Bad pool store, BAD!!!!

Here is the link to the overnight test:

Pool School - Perform the Overnight FC Loss Test (OCLT)

Good TFP and Matt, GOOD!

We got ya and understand how these things happen :hug: no worries!

Kim:kim:
Click to expand...

Thanks, Kim! I had a minor heart attack thinking I was going to need to drain my pool. I will do the overnight test tonight and see what happens. I tested yesterday and it looked to be around a 6 and just now it was at 5.5 using the drop test, but I will check again. I'm waiting to turn the SWG on until it gets back down to about a 3-4ppm. It's a struggle because I try to keep the FC as low as possible without anything growing thanks to my sensitive skin kiddo. So far the salt seems to be helping a lot though!
 
LD Stewart said:
.... I'm waiting to turn the SWG on until it gets back down to about a 3-4ppm. It's a struggle because I try to keep the FC as low as possible without anything growing thanks to my sensitive skin kiddo. So far the salt seems to be helping a lot though!
Click to expand...

This is going to be an issue. Mustard algae can survive in pools with low chlorine levels (at least how TFP defines low) because the algae produces beta-carotene as part of it's growth cycle (that's why it's yellow colored). Beta-carotene is a potent antioxidant that can neutralize chlorine.

Given all that you've posted here, your first order of business is to perform an OCLT to see if there is something growing in your water. You can't keep algae at bay if your water is loaded up with it. Then, after you've gotten your water clean and clear, you can see how well you can maintain your FC. Turning on and off the SWG is not the best strategy either - you need to dial in the % output setting and pump run times to give you a consistent FC output and hold the FC level in your pool stable. Allowing the FC to bounce around and possibly get to zero is just going to make your algae problems never-ending.

If you want to run your pool's FC levels on the low side, then you're going to need to supplement your sanitation or else you will always struggle with algae. The best course of action is to SLAM the pool to eradicate any algae present and then use a secondary sanitation process to help out. The problem is, there are three of them that I can think might help but only one of them doesn't add anything extra to your pool water.

Borates

Adding borates to pool water is normally done to help with rising pH control because borates act as a secondary pH buffer. However, borates are also a mild algae inhibitor and so they can help to keep algae growth in check. The downside is you would be adding something to your water and, as far as I know, there's no epidemiological data that would conclusively say that it would help or hurt your kids skin condition. So it would be a trial and error process but a negative result (worsening skin condition) would mean draining the pool to get rid of the borates.

Algaecide - PolyQuat-60

PQ-60 is the only algaecide that I would recommend using as it doesn't add anything to your water that would screw up the other chemicals levels (like the bromine did) BUT, once again, you're adding an unknown and so it could make the sensitive skin issue better or worse. The good news is PQ-60 is broken down by chlorine and so it would go away in fairly short order if you decided to stop using it.

Phosphate Removal

Sadly, this technique gets a bum-rap because pool stores have used it as a money-making device where they will often advise people to buy and use large quantities of phosphate remover even when it is not indicated. I prefer to blame the bad actors and bad information rather than the chemical itself because phosphate control is a widely used and chemically sound technique in many other water management situations. Removing phosphates from the water essentially starves the algae of a key macro-nutrient that is necessary for all life (nitrogen, phosphorous and potassium, NPK). While phosphate removal will never kill all the algae in a pool (it's not a sanitizer process), it can help to make the water less hospitable to their life-cycle and thus allow lower chlorine levels to be more effective. Phosphate removal requires knowing what your current levels are and if you have any sources of phosphate being added to the pool. If you use metal sequestrants, those typically contain phosphates. If your municipal water supplier uses phosphates for metal control, then that's another source. If the input sources of phosphorus are too high, then actively managing phosphates can get expensive and not be a reasonable strategy. You'd have to get your water tested to know where you stand or purchase a phosphate test kit (Taylor K-1106) to test your water yourself. It adds more work on your part but it's the only method I can think of that doesn't add anything else to your pool.
 
JoyfulNoise said:
This is going to be an issue. Mustard algae can survive in pools with low chlorine levels (at least how TFP defines low) because the algae produces beta-carotene as part of it's growth cycle (that's why it's yellow colored). Beta-carotene is a potent antioxidant that can neutralize chlorine.

Given all that you've posted here, your first order of business is to perform an OCLT to see if there is something growing in your water. You can't keep algae at bay if your water is loaded up with it. Then, after you've gotten your water clean and clear, you can see how well you can maintain your FC. Turning on and off the SWG is not the best strategy either - you need to dial in the % output setting and pump run times to give you a consistent FC output and hold the FC level in your pool stable. Allowing the FC to bounce around and possibly get to zero is just going to make your algae problems never-ending.

If you want to run your pool's FC levels on the low side, then you're going to need to supplement your sanitation or else you will always struggle with algae. The best course of action is to SLAM the pool to eradicate any algae present and then use a secondary sanitation process to help out. The problem is, there are three of them that I can think might help but only one of them doesn't add anything extra to your pool water.

Borates

Adding borates to pool water is normally done to help with rising pH control because borates act as a secondary pH buffer. However, borates are also a mild algae inhibitor and so they can help to keep algae growth in check. The downside is you would be adding something to your water and, as far as I know, there's no epidemiological data that would conclusively say that it would help or hurt your kids skin condition. So it would be a trial and error process but a negative result (worsening skin condition) would mean draining the pool to get rid of the borates.

Algaecide - PolyQuat-60

PQ-60 is the only algaecide that I would recommend using as it doesn't add anything to your water that would screw up the other chemicals levels (like the bromine did) BUT, once again, you're adding an unknown and so it could make the sensitive skin issue better or worse. The good news is PQ-60 is broken down by chlorine and so it would go away in fairly short order if you decided to stop using it.

Phosphate Removal

Sadly, this technique gets a bum-rap because pool stores have used it as a money-making device where they will often advise people to buy and use large quantities of phosphate remover even when it is not indicated. I prefer to blame the bad actors and bad information rather than the chemical itself because phosphate control is a widely used and chemically sound technique in many other water management situations. Removing phosphates from the water essentially starves the algae of a key macro-nutrient that is necessary for all life (nitrogen, phosphorous and potassium, NPK). While phosphate removal will never kill all the algae in a pool (it's not a sanitizer process), it can help to make the water less hospitable to their life-cycle and thus allow lower chlorine levels to be more effective. Phosphate removal requires knowing what your current levels are and if you have any sources of phosphate being added to the pool. If you use metal sequestrants, those typically contain phosphates. If your municipal water supplier uses phosphates for metal control, then that's another source. If the input sources of phosphorus are too high, then actively managing phosphates can get expensive and not be a reasonable strategy. You'd have to get your water tested to know where you stand or purchase a phosphate test kit (Taylor K-1106) to test your water yourself. It adds more work on your part but it's the only method I can think of that doesn't add anything else to your pool.
Click to expand...

Yes, I have the TFP test kit and no, I haven't been turning the SWG on and off. It has only been off the last 2 days because I needed the FC to come down after shocking it.

We've kept pretty low chlorine levels for the last 2 years without issue, but I made the mistake of not adding chlorine when the SWG installation got delayed and that's what started the algae issue. I have dark pebble plaster so it was barely visible until I brushed it and saw it coming off the sides. I am hopeful that it is dead now and we are good to go, but I'll do the overnight test tonight to confirm.
 

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