Balancing pool for winter + Pool store FUD = ???

[zephans]

(edited to fix missing sections due to greater than and less than signs.)
Well, I never got around to implementing more than B(leach) part of BBB. I'm really good at dumping lots of chlorine in, and I solved my green algea problem thanks to bleach. However I've had it above 20 for a long time and now I need to come back to earth.

Numbers:
per AquaQuip pool store in Lynnwood, WA using computerized "AccuraStrip"(?) + some liquid drop test.
(30min after pulling water from pool ~18" below surface):
Temp: 48 degrees (frosty at night lately)
Saturation idx: -.7
TDS: 400
CYA 80
T Chlorine 10*
Free Chlorine: 10*
PH: 8.2
T Alk 79
Adj. Total Alk 55
Tot. Hardness 45
Cloudy: No (thank goodness)
Green Algea: None (yeah)
Tester: Trevor
*Actual Chlorine is much higher. My guess is 20-25PPM for both F & T Chlorine.


There are several things that I need help for a smooth landing. My biggest issue is sorting out Pool store advice from what I've read hear + what I don't know.


1. Chlorine is through the roof. How much can I use my current numbers?
I haven't tried dilution testing yet (that will be in my next post). I mentioned this to the pool store guy but he didn't mention anything about changing the recommended chemicals to add to the pool. I know PH is likely reading artifically high due to Chlorine.
FYI: I haven't added Chlorine for 3 days and it still isn't down below dark purple limit (10PPM). I do have my winter cover on to keep leaves and sunlight away from the water (part of my algea clear-out + winterize plan)


2. Balancing chemicals for winter
Assuming I can use the numbers above, I need to balance out the pool to avoid swamp opening.
First I ran through poolcalc and found my 12'x24'x4' pool has 7700 gallons. (Aquaquip calculation says 6,800 which is 900 gallon difference. Volume calculation shouldn't be that hard to get right. I wonder who's more accurate?)
Going with 7700 gallons poolcalc gives me following for my posted numbers

TA 55 raise to 100: 81oz by weight or 61oz by volume Baking soda
I recall it's important to fix TA before PH
Per PoolCalc adding baking soda will also increase PH

PH 8.2 lower to 7.5: 24oz of 31.45% muriatic acid
Note PH likely high in part to high Chlorine
Fixing TA with baking soda will slightly increase PH.

Total (calcium) hardness 45 raise to 200:
5lbs of Balanc Pak 300 per Pool store (ingredients unspecified... Calcium I presume)
OR Add 177 by weight or 141 by volume of calcium chloride per poolcalc.
Numbers are per AquaQuip pool store. Took me a bit to realize this is CH in poolcalc.
I've read hardness isn't big concern for AG Vynil pool.
Pool guy says important for AG equipment. I honestly don't know.

Hey, how important is it to fix all this water balance stuff for winterizing? What would happen if I just leave things with strong chlorine and some polyquat(?) until sping opening?


3. Where to buy winterizing/algecide?
Pool store had winterizer on special. It's "Biogard Arctic Blue Algea protector" with main ingredient being metallic copper. Hey, I thought I read that it is best to avoid metal. I even noticed in the test results page that ideal Copper is 0. (I didn't get it tested because I know it's currently 0.) Pool guy didn't know anything about Polyquat or any other poly- algecide. He just said copper is the most common algecide. Anyone care to confirm or disagree with adding copper for winterizing? (I've never seen coppor recommended in pool closing posts)


4. Should I put salt in pool for winterizing or wait until opening?
I'm not going to install my small SWG that I bought with the pool until pool opening next year. However Salt would probably be enough to resist freezing in Seattle weather (20deg F is often lowest we get). It might also inhibit stuff from growing while pool is closed. I'll have to read PPM recommendation in my SWG instructios (I hope I still have them ).


OK, I gotta get some sleep (as usual). I hope this post gets some answers soon so I can quit worrying about our new pool for the winter. I also need to skim off the leaves and drain the rainwater that have accumulated over last week on the winter cover. I'll use siphon hose for now and possibly buy little pump (or better yet build a pool dome :-D ) later. For now I'm focusing on chemical balance.

 

[JasonLion]

Avoid copper algaecides, you don't want copper in the water. What we call polyquat most pool stores call something or other 60 or 60% strength. Usually seeing the 60% active ingredients is enough to tell you that you found it but sometimes it is offered at other concentrations. The active ingredient you want is "Poly [oxyethylene (dimethyliminio) ethylene (dimethyliminio) ethylene dichloride]", which is why we don't generally spell it out.

There is no need to worry about CH in a regular vinyl pool. You need CH if there is any plaster, pebble, tile, or rock work in the water (above the water line doesn't count). Some people keep the CH around 100-150 to reduce foaming, but if you don't have a foaming problem (most people don't) then there is no point in doing that.

It might be better to put the salt in later, though it doesn't make much difference. The only down side to putting it in now is that you might lose some water, and thus salt, when you close or over the winter.

You didn't say what your TA is now. If it is 50 or higher then don't worry about it till next season.

 

[zephans]

Thanks Jason. I just realized my initial post got mangled by having greater-than and less-than angle brackets in my text. I've edited the post. You can now see TA and Adjusted TA. I'm not sure what the adjustment is for, but that is what the pool store analysis says. Since it's over 50 I won't worry for now. Sounds like I can just return most my stuff and just order some Poly* for the winter. I am thinking I should try getting PH balanced a bit too.

 

[JasonLion]

It is difficult to measure PH when FC is high because FC above 10-15 interferes with the PH test. I am not surprised that FC is staying high with the cover on and the water cold. One way to get an approximate PH reading would be to get a bucket of pool water and leave it in the sun for a few days so that the FC level goes down. Then you could do a PH test on the water in the bucket.

 

[waste]

With reguards to adding salt: wait until next spring! The salt doesn't significantly change the freeze point of the water.

 

[zephans]

Thanks for all the suggestions. I really appreciate it.