pink algae and other problems

[PoolDoc]

oh and I had a question about a product called "aquafinesse" several places claim this would really help with biofilm and thus pink slime. Anyone have an opinion of this product?

Here's their MSDS page: http://aquafinesseone.com/msds-2/ There's nothing special in their products!

Do the pool chart, and I'll look at this in more detail this afternoon:

Pool Chart Entry Form
Pool Chart Results

Post when you've completed it, so I know to look back at this thread. I'm afraid you put enough bromine in to be a real problem. It certainly is enough to explain a high chlorine loss rate.

[matthew64]

chart is filled out.

I would agree about chlorine loss, but then again the loss was only 6ppm over the course of 2 sunny days! Only after I scrubbed the pink slime again did that next day the loss was greater (20 to 8) and the water was slightly cloudy that day after scrubbing.

[PoolDoc]

My bad on the chart -- still got to add better indexing.

Yeah, algal and bacterial 'goo' has a HUGE chlorine demand, that must be satisfied before you can make everything 'all better'. However, given your high CYA, the bromine may be helping more than it's hurting, since the bromine creates a larger 'active' halogen residual than you'd have otherwise.

Given that you have a vinyl pool, draining is not a practical option.

But you likely don't have 35K gal; I'd actually flagged that. Here's the calculation:
18 x 40 x 3.5 x 7.48 gal/cft = 18.8K gal (top 3.5' slice of your pool)
18 x 18 x (8-3.5)/2 x 7.48 = 5.4K gal (assumptions: break at 20'; hopper volume is 1/2 of a non-angled bottom - reasonable for most liner pools)
Total gallons = 24.3K gallons.

Still, that's a fairly large volume, and the bromine may not be a long term problem. If it is, you can do a fairly effective drain, if you buy an over sized winter cover. I'll explain how, if that becomes necessary.

[matthew64]

Thanks for the correction. The 35,000 gallon was a quote from the previous owner and I just never questioned it. Anyway so I guess just try to continue to keep it a high chlorine level (20ppm) for the foreseeable future and see how it goes. thanks for all the help.

[PoolDoc]

Actually, with the bromine present, it probably isn't necessary to keep the chlorine so high. The bromine creates a significant unstabilized halogen residual that is effective against biofilms like you have.

I'd let the chlorine drop, at least to 10 ppm, as soon as you've brushed all the 'pink algae' and seen no evidence of new growth.

[matthew64]

So I have been keeping the FC at around 20 (as high as 24) for several weeks now, have brushed and vacuumed the pool multiple times and yet the pink stuff still returns. it mostly appears as more dead particles on the bottom of the pool, but there is new formations on the walls. Im worried that Im creating the most chlorine resistant super bug ever.

[PoolDoc]

Hm-mmh.

My problem is that I have ZERO personal experience with pink algae (it's not actually algae), and very little information about what might be most effective. Complicating the issue is that it is an opportunistic biofilm community that's going to tend to stick around in cracks and crannies even after it's 'all gone'. So, you not only need to get rid of it, you're going to have to keep getting rid of it.

What do you want to do?

Option #1: I looked at your pool online (Google Maps has a very nice image of it!). Since you've got no steps, you can probably drain to 8" deep in the shallow end, without too much risk. That will give you about a 60% drain, reducing your CYA to ~140 ppm. Then you can refill and treat with high chlorine. You can also go to 60 ppm borates, which may, or may not help but will reduce your pool's susceptibility to true algae.

Option #2:Try chemicals till you find what will work. I suspect the cheap quat algaecide at Sams Club will work . . . if you add enough to make your pool soapy and THEN brush. You'd only be out $30, but your pool will be soapy and probably irritating to eyes for maybe 2 weeks. You could try polyquat which is more expensive, and may not penetrate the biofilm well, though it might help if used at the same time, as the other. You could use ammonium chloride, to produce monochloramine which penetrates biofilms MUCH better than regular chlorine . . . but monochloramine is irritating.


Honestly, if it won't bust your budget, I'd probably try this in your shoes:

• Do a 50% drain (8" water in the shallowest stpot) and replace => $###?
• Add 60 ppm borates (19 boxes of 20 mule team, plus maybe 6 gallons of muriatic acid => $100)
• Add 1 pint of polyquat and brush every 3 days for 2 weeks (3 x $20 => $60)

If that doesn't work . . . you can move on to the foamy quat + monochloramine. But the first 3 steps are all stuff that's generally good for your pool, ANYHOW, so there's no waste. And, none of that will put your pool out of service, except for the time it takes to refill.

One BIG caution: do NOT do this if the ground around your pool is wet! If you're not sure, dig a post hole next to your pool. Let it stand overnight. You can drain to 1 foot ABOVE the highest water level in the hole.