vacation suggestions

[boomer99]

I will be out of town for about ten days and need to "close" my 12000 IG vinyl-liner pool while I'm gone (actually I have no choice). I was thinking of simply turning off the pump, putting on my solid winter cover and leaving. My usual numbers are: ph 7.8, alk 110, CYA 30, Total chorine 5, never any combined chlorine. Water temp has been between 70-80 past two weeks, outdoor temps between 75-90 high and 55-65 low.

Does anyone have any experience on what I should expect when I return? This seems similar to closing in the fall, except I won't be blowing out the pipes like I do in the winter. Usually, in the spring, we can swim within 72 hours of opening, with a little debris in the water but no algae problems visible or any difficulty maintaining a chlorine level.

Should I keep a "shock" chlorine level for a few days before leaving? Should I raise my CYA level? I have been adding 60% poly algacide every week for the past month or so and have no apparent water problems now.

Thanks for any advice or experience you can share.

[CarlD]

First off, leave your pump and filter running. You should have a timer so 10 hours a day is probably fine.

If you have nobody to add chlorine then you'll want to run the pool up to shock levels for the CYA you have.

But if you buy a simple $10 floater and fill it with Tri-chlor pucks, under the cover, you should keep you FC nice.

But if you do that, I personally would first add Borax until the pH was 6.7 to 6.8. The Tri-Chlor will lower it on you (been there, done that)

I once left my pool covered for two weeks with four floaters filled to the brim adjusted for max distribution.

When I came back, my CYA had gone from 30 to 60ppm, my FC was fine, there was no algae, but my pH had dropped below the measurable 6.8. A lot of boxes of Borax went in fast! Luckily my liner was undamaged.

Or you can take a couple of gallon jugs of bleach, punch pinholes in them, and leave them floating in the return stream.

[Watermom]

I think Carl made a typo in his post above regarding the ph level he would take it to before starting to use trichlor. I think he meant to say 7.6-7.8. Trichlor is very acidic and will lower your ph. So, you'll want to start with it a little towards the high end of normal before you leave.

[boomer99]

Thanks for the helpful advice. I wasn't clear on the first post, but I'm afraid I will have to turn off the pump and cover the pool while I'm gone. I decided to give it a good shock for 24-48 hours before leaving and add a little extra poly-60. I will post an update when I get back, either to ask for more help with my new "pond" or to share a positive experience with others who might need to travel in the summer. I hope its the latter.

[CarlD]

I think Carl made a typo in his post above regarding the ph level he would take it to before starting to use trichlor. I think he meant to say 7.6-7.8. Trichlor is very acidic and will lower your ph. So, you'll want to start with it a little towards the high end of normal before you leave.

That's right--high but acceptable pH. Just a typo on my part.

[ChuckD]

I've been thinking about this closing stuff, wondering about what's actually happening, and am starting to question parts of it. To wit: Shock and Poly-60.

It's understood that the Poly-60 will hit the Cl level hard (unknown how much it takes to knock X ppm Cl down to Y). But what's the reasoning behind the shock? If your water's shown no CC and no traces of algae for weeks previous. Cl will then serve no immediate purpose, and since it dissipates pretty quickly to zero, if it's not knocked out by the Poly-60 dose, it certainly serves no long term purpose.

So what's the point of the shock?

The only real long-term protection you can have is the algacide. It's starting to make sense to me that just a normal dose for a week or three absense, or a double dose for winterizing might be all that's needed.

Am I missing something?

[CarlD]

ChuckD,
You may be right, but my thinking is like this:
Pre-lim: Wait till pool is in the 60's or high 50's.

1. Shock the pool to get it virtually sterile
2. 1 quart of polyquat to inhibit algae growth. This, in 48 hours drives the FC to near 0.
3. Shock the pool again to kill any trace of anything.
4. Cover and close. The cover prevents UV from breaking down FC, and there should be CYA in the water too. The water's cold as a further inhibiter.

I open every spring to clear water, just dust and dirt on the bottom that the Blue Diamond clears with 3 or 4 cycles. I never have algae or a cloud in the spring.

Does the end of season shock matter? I don't know. Maybe not. But it ain't broke so I'm not fixin' it.

What's the risk? I use 6 gallons of bleach in the fall, and no algae in the spring. What if I don't use those 6 gallons and I have a bloom in the spring? It will cost me a lot more than 6 gallons of bleach to clear it.

I could roll the dice, but the upside is saving $10 on bleach, the downside is spending $30 or $40 extra to clear a bloom.