Mustard Algae and Sodium Bromide (Long)

[tundraSQ]

The Sodium bromide has created a bromine bank in your water. Every time you shock with chlorine the chorine is 'converted' into bromine until the bank is exhausted. Just keep shocking. This is why your chlorine is not holding. It is reactivating the bromine. I would be careful about overdosing on the sodium bromide because it can create a VERY LARGE chlorine demand. Just give it time to work and keep shocking unitl the algae is gone and your chlorine is holding. (and don't forget to BRUSH, BRUSH, BRUSH!)

BTW, this is not very different then running a spa on sodium bromide...sodium bromide is added to the water and then chlorine (usually bleach, cal hypo, or dichlor) is added to activate it. When the bromine level drops you add more CHLORINE to reactive the bromine!

Thanks...I am going to keep hitting it with chlorine..but yes it is gobbling it up. I would say i am going to be going thru 25 liters over 24hours for the second straight day. But i see no signs of the algae in the pool tonight..we'll see what shows up in the morning. Yes i am running the filter 24/7 and brushing often. Before adding the bromide I had no real clue as to how long it would take or that it would gobble the chorine...but thanks to you I now know what to expect.

[tundraSQ]

I noticed that my PH has climbed (maybe the heavy rains) but it is at about 8....I am kind of thinking that is from the clorox and the rain...should I just leave that alone while i am fighting this algae for now? Or should I throw some acid in the mix? My gut says to leave it for awhile...

[waterbear]

Bromine is effective at a wider pH range then chlorine and if I am not mistaken the mustard products work better at a slightly higher pH. You might just want to bump it down to about 7.6 or 7.8 for now.

[tundraSQ]

I may have killed off all the litle mustard algi!!!

I woke up to a clean pool and it held alot of the FC over night. I topped it back up this morning and came home just now to a clean pool (aside from the tent worms) and I still have about 10ppm FC ( where as yesterday afternoon I came home to about 2ppm from the same starting point in the morning) in the pool. I am going to still keep the levels at shck levels for a few more days just to be sure...but I may have turned the corner thanks to you. Plus t he PH seems to have dropped to 7.6 on its own today....

So Next up i am going to raise my CYA and get my TA to come down some...but first I needed to kill this algae.

Thanks for the help...and fingers are crossed.

[waterbear]

GLAD TO HEAR IT! Seems like you have turned the corner and I agree with keeping the chlorine up for a few more days to be sure.
Don't try to adjust the TA until the chlorine is below 10 ppm (there can be interferances with the pH and ALK tests from high chlorine) and you can probably add some CYA in the next day or two. Just remember not to clean your filter for a week after adding it becuase it takes that long to dissolve!

[tundraSQ]

crap.....a trace was spotted this morning....i brushed and vacuumed in the rain....this stuff is NOT fun...

FC was 11 when I checked before bed...I added 5qts just to be safe...and it held during the night...but with a residual amoutn of this algae on the bottom this morning...should I be adding more sodium bromide tonight? I would think if I had any bromide left in the pool then the FC would be be dropping alot over night?

[waterbear]

Might not hurt to go through it one more time and keep hitting it with chorine heavy. Usually once takes care of it but mustard can be a problem to kill off. You also might want to consider switching guns ( cannons?) and giving polyquat a try. People have reported good results with it against mustard.