Did I just waste my Polyquat?

[Leehicks79]

I read a few posts on winterizing so I brushed the pool, raised my chlorine to shock level and put in a quart of polyquat (we have visible algae I believe). But then I read where the polyquat will just filter out if the pump is not on recirculate. Is this true??? No algae this morning....do you think I will have to re-dose or will keeping it at shock levels with bleach be sufficient?

[Leehicks79]

Update....after an hour or two in daylight, small pockets of algae we're starting on the floor of the pool.

Yesterday, before shocking, my FC was 3.5 and CC was 0. I added 2 gal of bleach, which took my fc to about 17 then added polyquat. This morning my fc was 11 and cc was .5. I added 12c of bleach, estimating that would take my fc above 15. Should I be doing anything else?

[kelemvor]

I'm not sure about the filter filtering it out. If your chlorine is at shock level, I'm pretty sure the chlorine will eat it up.

If you've got visible algae in the pool you'll stand a much better chance of opening to clear if you kill the algae and filter it first. With 17 FC and algae still visible, it makes me wonder what your CYA level is.

[Leehicks79]

Cya is 40. Maybe it's not algae? But when I backwash, the water in the sight tube definitely has a greenish tinge to it...

[CarlD]

IF you have algae, the Polyquat is only partially effective against it, but chlorine is better. What you need to do is raise your FC to shock level and keep it there till the algae has been gone for at least 24 hours.

My preferred method of then adding the Polyquat, waiting for the FC to tumble, then raising it again, is based on the pool being algae-free FIRST.

I've never heard of the Polyquat filtering out that way, rather than you shouldn't backwash or vacuum to waste for about 48 hours at least. In my closing method above I always am running the filter. So I don't think your Polyquat is wasted.

[Watermom]

Carl, I think the Polyquat does come out on the filter so best to put it on recirculate after it is added.

[CarlD]

Really? I've never had a problem with my method. Of course, I shock my pool till it's clean before the PQ goes in.

[chem geek]

Polyquat itself is far too small a molecule to get caught even in a DE filter or in a slime bag. However, Polyquat coagulating with particulate matter in the pool will get filtered out since Polyquat is not only an algaecide but is also a clarifier. However, this won't happen if your pool is clean.

[CarlD]

Polyquat itself is far too small a molecule to get caught even in a DE filter or in a slime bag. However, Polyquat coagulating with particulate matter in the pool will get filtered out since Polyquat is not only an algaecide but is also a clarifier. However, this won't happen if your pool is clean.

Thanks Richard. That's a GREAT explanation and it fits both Lisa's and my scenarios perfectly: If the pool is messy the PQ will tie particles up that then pull both into the filter medium. But if the pool is clean, the PQ will pass through the filter and into the water.