Visalia 25k Gallon Filling Now

[Fuzz1]

Visalia 25k Gallon Filling Now

I'm in the process of filling a pool that has been empty for a few years. I'm looking for some help in getting the water balanced. Here's the particulars.

Location: Visalia, CA
Weather: Very hot and dry, >95 deg most days.
Type: In-ground, concrete/plaster.
Size: About 25k gallons (will measure more accurately soon)
Filter: Sta-Rite PLM150
Controller: Intermatic P1353ME Multipurpose Control timer
Filter Pump: Pentair two speed (HP 1.0/.12)
Booster Pump: 3/4 horse Franklin Electric 778 (for Polaris)

Water Source: City supplied tap

It has been filling over night and is close to half full now. Here's the current readings using a Wal-Mart HTH 6-way test kit...

CL: 5ppm
PH: 8
CH: <40
TA: <30

The chlorine is from me putting in about 1/2 gallon of 8% Soduim Hypochlorite last night before I went to bed.

Assume for now that the pool is 25k gallons. Whatever numbers are appropriate for that I will moderate down somewhat and ease into it.

Here's what I think I'll be wanting to purchase today...

-Baking Soda to raise TA without raising PH
-Calcium Chloride to raise calcium hardness
-Muriatic Acid to lower PH
-Cyanuric Acid
-Calcium Hypochlorite or Dichlor or Trichlor for chlorination since I also need calcium and CYA

1) What's your best guess on the quantities I'll need of the chemicals listed above?
2) Do I need more calcium than what I can practically add via chlorinating with Calcium Hypochlorite?
3) Do I need more cyanuric acid than I can practically add via chlorinating with Dichlor or Trichlor?
4) Should I hold off on lowering PH via Muriatic Acid until I have the CH and TA up to normal levels? I figure my current Saturation Index is (assuming 76 degree water) about -0.5.

I guess that's about it. I've got another 12 hours at least before it'll be full enough to start the filter. You guys buoyed my sanity back years ago when I first built a pool, and I thank you from the bottom of my heart. I'm looking forward to another dose of your sage advice again.

[BigDave]

I like starting new water with dichlor, it dissolves quickly and adds 9ppm CYA for every 10ppm FC. It's also helps lower pH which your water needs. 25lbs of dichlor should get 25000 gallons of water to 60ppm CYA - a bit higher than we usually recommend but higher CYA can help mitigate FC loss due to heat and sun (is it sunny on your pool?).

Just use dichlor to chlorinate the pool - following Ben's Best Guess Chart until you've used up all 25 lbs then your CYA should be 60. Perhaps you should take a CYA measurement after adding 15 lbs (should be 36ppm CYA) to be sure we're not way off. Every pound of dichlor should add about 2.7ppm FC - use that as a guide to chlorinating. Don't forget to increase your target FC as the CYA builds (12ppm CYA for every 5lbs dichlor).

Be cautious when buying dichlor - many retailers add copper, detergent, other junk that you do not want fouling the new water. Sam's club may have pure dichlor (99% dichloro....). Wall mart probably doesn't. If you search around the forum, you'll find alot of disussion about adulterated dichlor and links to Amazon source of the good stuff. Leslie's also sells pure dichlor (last time I checked) but it's pricey.

While maintaining normal FC levels with dichlor you will be able to adjust TA and pH.

When the CYA goal is reached, start chloinating with CalHypo or bleach (liquid chlorine). Don't let the undissolved dichlor come into direct contact with any form of hypochlorite - things can go boom.

[Fuzz1]

Thanks Dave. The pool is in direct sun with no shade. That's about what I was thinking re the Dichlor to add the CYA. Would Trichlor add about as much CYA as Dichlor? I never had a good grasp of the difference between the two.

What about the calcium? Isn't that something I want to get in there right away to prevent corrosion of pipes and leeching from the walls? Or is that something that's not a big emergency, and I can chlorinate with Cal-hypo and Dichlor-Trichlor for a while to bring the CH/CYA levels up?

[BigDave]

I haven't personally had to deal with Calcium (vinyl pool with ~150 CH in the fill water), but I would think you'd want to take care of that directly instead of waiting for it to build with cal-hypo.

I recall that Trichlor adds 6 ppm CYA for every 10ppm FC so dichlor will get you there faster. Trichlor is also usually available in slow dissolving pucks/sticks dichlor dissolves pretty quickly. Remember, you'll need to test / chlorinate several times a day until the CYA starts to build up.

[CarlD]

I know I've been away for a while but maybe I can help.
While it's certainly possible to mix and match using di-chlor, tri-chlor and Cal-hypo safely, I think it's a bit too confusing to be practical. Pick one and work with it.

If you want to add Di-chlor, expect it will help with CYA (as Dave describes) but plan on adding calcium and muriatic acid and baking soda. Di-chlor isn't nearly as acidic as Tri-chlor.

If you want to add cal-hypo, expect it will help with calcium levels, but you'll need to add stabilizer, muriatic acid, and baking soda again. Cal-hypo isn't acidic at all

If you want to add Tri-chlor, it will work differently in that it is an eroding tablet. I like to use two floaters loaded with tabs when I am using it. This will be very acidic, will add CYA, albeit more slowly, and provide a more constant level of FC as it erodes. You'll still need to add calcium, and baking soda. You may also need to get to your maintenance level of chlorine using bleach. But this can be a painless way to three things at once.

Finally, you can do it all by adding bleach/Liquid Chlorine (my favorite), Calcium, Muriatic Acid, Stabilizer, and Baking Soda. Having a vinyl pool I don't add calcium, but I have used Cal-Hypo and don't care for how long it takes to dissolve.

A week ago I just got back from being out of the country for a month and returned to a pump our house-sitter had blown up, and a general mess. Over a foot of water had been lost (nearly 5k gallons). FC was down, pH was up, CYA was down, Alk up, salt level down. I added 120# of salt, one gallon of 12% LC, 4lbs of CYA, and about a pint of Muriatic Acid. Now the FC is around 6, CYA is 60, pH is 7.4, and salt level is an ideal 3000ppm.

But it's raining so we can't use the pool now!

[BigDave]

Welcome Back CarlD, sorry to hear about your pump. Wasn't it new this season?

[Watermom]

But it's raining so we can't use the pool now!

Yeah, cuz you might get wet!

(Sorry to hear about your pool.)

[BigDave]

Yeah, cuz you might get wet!

[CarlD]

Yeah, cuz you might get wet!

(Sorry to hear about your pool.)

LOL!
Yeah, I might melt. Actually it gets cold as.... no sun, cold water...BRRRRR!!!

The pump IS new this season. Luckily, with some replacement plumbing it seems OK. I did order a new casing (far less than a pump) in case the threads were stripped.
The pool is fine now, the water is fine again and the boys and I were in it today!