Chlorine Higher than 15ppm

I am curious as to whether anyone has ever bleached out their vinyl liner with higher than 15ppm chlorine to use for shocking? I have seen where some people are going higher than Ben's recommended 15ppm max for vinly liner pools, and wonder if going higher for at least a few days, would give an extra kick on mustard algae that 15ppm might not do?

I know when I had my new liner installed a few seasons ago, I kept a remnant that wasn't needed, and poured a bit of straight bleach on it to see what it would do, and it didn't bleach it at all. So, I am just wondering with all the dilution of water, if going above 15 for a few days max would be ok or too risky, and worth the risk? If going above 15 ppm is possible, how much higher would you suggest, max?

Thoughts??!

John

What is your cya?

I will be checking cya tomorrow. I added more last weekend. I had added some in the skimmer, not a sock, the week before and we got 8 inches of rain, and had to drain the pool down a good bit, so I am sure I lost that batch, and will get a new number tomorrow.

John

The reason I asked is that the amount of cya will determine how high your shock levels need to be, and how high you can go before bleaching the liner.


Stabilizer . . . . . . Min. FC . . . . Max FC . . . 'Shock' FC
=> 0 ppm . . . . . . . 1 ppm . . . . . 3 ppm . . . . 10 ppm
=> 10 - 20 ppm . . . . 2 ppm . . . . . 5 ppm . . . . 12 ppm
=> 30 - 50 ppm . . . . 3 ppm . . . . . 6 ppm . . . . 15 ppm
=> 60 - 90 ppm . . . . 5 ppm . . . . . 10 ppm . . .. 20 ppm
=> 100 - 200 ppm . . . 8 ppm . . . . . 15 ppm . . .. 25 ppm

I'm sure you can go a little higher than what is on the chart, but I wouldn't push it. If you maintain the ppm you need to shock, then your algae will clear, as long as you stay consistant with keep the water at shock levels.

Marie, here are my numbers as of this morning:

FC 12.5
CC0
PH 7.3 (down a bit from the rain yesterday, I assume)
Alk 90
CYA 35

So, I will just try going up to about 16, and maybe 17 max and cross my fingers I have no liner bleaching! Just plan on doing this through Monday, and reevaluate the mustard algae situation. It appears to be mostly gone at this point. Not sure if it is dead, alive or what, but the amt. is much less, and with running chlorine at 15 as often as I can for this last week, I would think it would be dead or nearly dead by now. I vacuumed this morning and will see what it looks like in the morning.

Thanks,
John

I think this plan is right on. Make sure you vacuum to waste the algae that you see. I know that mustard algae is tough to get rid of, but it sounds like you are on the right track! I would vacuum to waste, backwash and keep the chlorine level at shock for a couple of more days to be sure that it is all gone.

In my experience, mustard algae never really go away 100 %, since I do believe it comes from the rain. You'll notice that it pops up more after a good rain, than if there's a period of dry weather. If you're in the midwest, this year it's seems to be a bit more frequent. I've talked to other pool owners in the area and they're saying the same thing. Last year we were in a drought, so i didn't see much of it except for the few times it did rain. Just have to keep the Cl level a little higher this year. I have an AG 20,000 Gal vinyl and keep my Cl between 5 - 10 ppm, and shock at 15 - 20. Doesn't bother the liner at all. If your Cya is high, you may have to shock higher. Check the chart. The key is to vacuum it as soon as you see it. A third of my pool is in the shade from a backyard tree for about 8 of the 13 hours of sunlight I get in mid summer. I'll notice maybe 6- 8 little half dollar sized spots come up every 4 -5 days in the shade. No big deal. I just vacuum them up and they're gone. The algae isn't very hearty, it's more like a dust that settles at the bottom, as I thought this was the case at first, until I did research on it.

Mine has only been very minimal spots on the pool floor. Looks like dirt/dust to me, but pool repair guys have both said it was mustard algae.

Sounds like it can get out of control though.

I don't use my pool vac at all since getting the PoolBuster Max CG. That way, I feel better, knowing it isn't going through the pump or filter at all. With the micro fine filter bag on it, it is amazing what it sucks up. Love that vacuum!

John