How Do I Kill White Molds and Pink Slime?

[smullins34]

-- We don't allow users to run parallel threads here and at other forums. It's not fair to us or to the other forums. The OP objected to the limitation and asked to have account removed. I removed it. But I've to kept this thread open and use it to collect OTHER experiences with water mold or pink slime. --

We've been having a lot of trouble with our Jandy 1400 SWG this year. We opened the pool early and a week later, we got error 121, so after going through a bunch of stuff we replaced the cell. Then we have been dealing with errors 123 and 188 for a couple of weeks. Looks like we might have it fixed with a replacement DC cord.

In the meantime, our water balance has gotten out of control. CYA had been low (according to pool store) and we just couldn't seem to get it up. Even after dissolving it in various manners and adding and adding. Then all of the sudden, this white, tissue-like, slimy gunk appeared. It looks to be White Water Mold. We decided to open up the filter to see if the CYA was getting caught up in there or something. When we did, we found that it was completely clogged with pink slime.

We replaced the sand last Saturday and have been shocking the pool every day. We checked the filter today and there was a little in there, but nothing like it had been. We've been shocking and brushing the pool every day.

It keeps popping up - mostly around fixtures and on the side walls. The light is out of its socket and it's still growing around the light. How can it be growing in these high chlorine levels??

FC - 20.5
CC -1 (started at 3.5 last week)
pH - 7.2
TA - 90
CH - 390
CYA - 80

[waterbear]

These biofilms are resistant to chlorine and can need very high levels Is your pool vinyl, fiberglass, or plaster? If the latter two you will need chlorine up to around 50- 75 ppm and keep it there to kill them off, If you have a vinyl pool it gets trickier and requires a bit more work so as not to bleach the liner. You would need to turn off the SWCG and use a sodium bromide product and then shock to bring the chlorine up to about 10-12 ppm (bromine to about 22-27 ppm) since bromine is not stabilized by CYA this takes your 80 ppm CYA out of the equation and give you a higher activity for killing the biofilm and less likelyhood of bleaching out the liner (but some bleaching will still probably happen). You would need to keep the SWCG off and keep shocking for about a week or so of adding the sodium bromide until you have killed all the biofilms and see you are not losing sanitizer quickly during the day. Since inorganic bromine cannot be stabilized for loss from UV light the sun will quickly deplete your iso you will need to shock again to 'reactivate' the bromine. Once you find that your santizer levels are holding after the biofilms are gone it means that the bromine pool has converted back into a chlorine pool and you can turn the SWCG back on.

[BigDave]

Sounds like you're gonna need more chlorine.
What have you been using to shock?
I believe Pink Slime and White Water Mold may need the Super shock level to beat.

[smullins34]

Sorry, I should have given you more info about the pool. It is 36,000 gallons, underground, vinyl. Our liner is on its last legs. Barely hanging on in some spots. It is already fairly bleached out around the waterline. I honestly don't know how old it is, but suspect it is original to the pool - built in 2003 - as nothing else had been replaced when we moved in.

We've been trying to keep the FC close to 30 with liquid bleach. Although, we haven't been on it 24/7 and it has probably been around 15ish most of the time. Tonight before we added more I tested it at 25.5 with CC at 1.

[waterbear]

30 ppm FC at 80 ppmCYA just ain't gonna cut it!

[smullins34]

I was going by a table on trouble free pools. Where should we aim?

[waterbear]

I was going by a table on trouble free pools.

And there we have it!

Where should we aim?

I did already answer that before!

If you have a vinyl pool it gets trickier and requires a bit more work so as not to bleach the liner. You would need to turn off the SWCG and use a sodium bromide product and then shock to bring the chlorine up to about 10-12 ppm (bromine to about 22-27 ppm) since bromine is not stabilized by CYA this takes your 80 ppm CYA out of the equation and give you a higher activity for killing the biofilm and less likelyhood of bleaching out the liner (but some bleaching will still probably happen). You would need to keep the SWCG off and keep shocking for about a week or so of adding the sodium bromide until you have killed all the biofilms and see you are not losing sanitizer quickly during the day. Since inorganic bromine cannot be stabilized for loss from UV light the sun will quickly deplete your iso you will need to shock again to 'reactivate' the bromine. Once you find that your santizer levels are holding after the biofilms are gone it means that the bromine pool has converted back into a chlorine pool and you can turn the SWCG back on.