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.

[haze_1956]

I found it interesting that the CYA was at 0

Wondering if the algae ate it last fall and then froze and dropped to the bottom.

[CarlD]

My CYA dropped from about 40 to 25 over the winter...but I had lot of dilution from rain and snowmelt

[chem geek]

Many people find their CYA level dropping to 0 over the winter. Though it is possible that algae eat it for food, what IS known is that there are anaerobic bacteria that normally live in soil that definitely consume CYA. It is very possible that at least for pools where the FC gets to 0 that these bacteria consume the CYA. If they do, then they produce ammonia as a by-product which would mean needing LOTS of chlorine to open a pool.

Some users report the CYA dropping over the winter even maintaining chlorine levels. This happened to me this winter going from 20 to 10 (approximately) and I had no dilution (I have an automated opaque pool cover), but in past winter's I hadn't seen this and I've maintained chlorine levels every winter.

Richard

[haze_1956]

Alk is down too. 120 to 70.

Lot of start up this year !! LOL

Hate it when an experiment turns around and bites me in the wallet.



I'll use poly this coming Fall and see what I find in Spring 2008.