Polyquat or not ?

[haze_1956]

Result of experiment of whether to add Polyquat at closing.

Closed with Poly in fall 2005 and opened in Spring 2006 to clear water and clear bottom with CYA reading of 30. Believe it was 30-40 at close.

Closed in Fall 2006 without Poly. Opened in Spring 2007 with clear water, but a film of dead algae on the the bottom and a CYA reading of Zero.

Just wanted to post info for comparison by others. Maybe we can gather enough info to see if there is a correlation.

[CarlD]

I always close with poly. No algae on the floor but LOTS of black/brown soot/dirt/pollen. And clear water. Just comes with living in NJ. Even cloths in closets get covered in dust fairly rapidly. The Blue Dolphin gets it with 2 or 3 cycles.

[NWMNMom]

I have never closed without. I'm too scared at what I would find.....

[ChuckD]

This may be a testament to how a Cl shock will kill your Poly: I closed last fall with a double dose (half gal. in 20K of water) and then a shock, and while I can see the bottom in the four foot end, the deep end is dense green. I also use only a mesh leaf net as a cover.

[chem geek]

Note this post where a chemist at Buckman Laboratories gives the recommended closing procedure which shocks with chlorine first, then lets the chlorine level drop before adding PolyQuat.

Richard

[CarlD]

OK, here's how I do it and EVERY season I open to clear water. I take into account that the PolyQuat in large amounts causes the FC level to collapse. But I don't do this until the water is AT MOST in the low 60's, colder is better.

1) shock the pool

2) Add 1 quart of polyquat.

3) Wait 24 hours for the chlorine to drop.

4) Shock it up again.

5) Close

Yes, it's really all it takes.

[ChuckD]

Note this post where a chemist at Buckman Laboratories gives the recommended closing procedure which shocks with chlorine first, then lets the chlorine level drop before adding PolyQuat.

Richard

Right, Richard, very familiar with that post and knew about the nullifying effects at higher concentrations. Thanks for the info. My pool's not at my primary residence tho, so I didn't have time to wait for Cl levels to drop. Just the weekend.

But I have a follow-up to that referring to your comment about the 'heavy molecular weight' of the Polyquat and another, as yet unresolved controversy concerning it. Some here say that a DE filteration system will filter out the Polyquat, I remain unconvinced. Do you think, given its higher weight this is a concern? I don't have a bypass, or circulate-only mode on my Hayward EC-65, so it's a real concern for me.