100,000 gal pool

[4dks1]

It hasn't been clear since Labor Day 2013! We've spent hundreds & hundreds of dollars in the last 10-11 months!

I was thinking of trying the 15% chlorine. Where do you buy it?

We have a Basic OT test kit, but we usually have the water tested at pool stores.

We've been told to drain it.

We just replaced some of the filter grids.

[CarlD]

That is a BIGGG pool! And it's a private residence?

Good luck finding 15% Liquid Chlorine! However, here in NJ, 12% is available in 2.5 and 5 gallon carboys. The place I get it from has so much turnover that their "12%" usually tests at 14-14.5%

With YOUR pool, figuring how much Free Chlorine a gallon will add is easy: Just multiply the percentage of the concentration by 10. So 1 gallon of 15% will add 1.5ppm of FC. 1 gallon of 8.25% will add .825ppm of FC.

But we do need a full screen of pool tests to be able to help.
That would be:
Free Chlorine (FC)
Combined Chloramines (CC) or Total Chlorine (TC)==> TC = FC + CC so if we have 2 we get the third.
pH
Total Alkalinity (TA or T/A)
Calcium Hardness (CH)
Stabilizer/Conditioner (CYA/Cyanuric Acid/Isocyanuric Acid)

Two carboys of nominal 12% run me about $35-$36 and, if they test at 14%, will add 14ppm of FC to your pool. Yeah, you'll need at least that much, maybe more, every dose, and you'll need multiple doses. But 100,000 gallons of water will probably cost far more.

If it turns out your stabilizer is low, Di-Chlor powder may be the way to rapidly raise both FC and CYA levels.

Ben is usually the best person to handle very large pools, but this is the first I remember that wasn't a public or commercial pool.

[PoolDoc]

100,000 gallons is big enough to be different . . . and expensive.

1. Is this a commercial pool?
2. What pump and filter do you have? (make / model / size / type)
3. What sort of chemical feed system do you have?
4. If it's not commercial, are you committed to operating this thing?

[4dks1]

Hi, it is not a commercial or public pool. Yes, it would be great to get it going again.

Pentair DE filter FNS Plus 60
Pentair Whisperpro pump

Chemical feed system-chlorine


Size 260"x260"x272" pool 96" spa

[PoolDoc]

+ 15% chlorine is hard to buy at the consumer level, outside of south Florida. It deteriorates rapidly at summer time temperatures, so IF you get it, you need to make sure it's fresh. I think there may be some places in NJ and California where it's available . . . so you may be able to find it, but that's a local question we often can't help to solve.

Keep in mind, 15% chlorine is a bit different. For example, it will start a fire if you spill it on a pile of cotton rags!

+ You definitely need a K2006 kit. Especially with a 100K gal pool, you don't want to add unnecessary chemicals. See http://pool9.net/testkits/

+ If the pool does not have really high stabilizer, the best place to start would probably be to get 1 or 2 50lb buckets of dichlor at Sams Club. They are one of the few retailers selling un-diluted dichlor, and at a really good price, too. Dichlor dissolves quickly, so it's easy to add, and it builds up your stabilizer level rapidly. Of course, if your CYA is already too high, that is not a good thing.


PoolBrand granular dichlor 50lbs (http://www.samsclub.com/prod4340004.ip) @ Sams Club => ~$2.20/lb (May 2014 in Chattanooga)
PoolBrand dichlor bagged shock 24lbs (http://www.samsclub.com/108822.ip) @ Sams Club => ~$2.50/lb (May 2014 in Chattanooga)

Kem-Tek dichlor 22 lbs (http://www.amazon.com/exec/obidos/ASIN/B0030BEHZA/scouscho-20) @ Amazon => ~$3.50/lb (May 2014)
Kem-Tek dichlor 12 lbs (http://www.amazon.com/exec/obidos/ASIN/B0030BEHZ0/scouscho-20) @ Amazon => ~$4.10/lb (May 2014)
Kem-Tek dichlor 5 lbs (http://www.amazon.com/exec/obidos/ASIN/B0015UIOWK/scouscho-20) @ Amazon => ~$5.00/lb (May 2014)
Kem-Tek dichlor 2 lbs (http://www.amazon.com/exec/obidos/ASIN/B0030BEI40/scouscho-20) @ Amazon => ~$9.00/lb (May 2014)

Keep in mind that Amazon products normally ship free; and that in many parts of the country, you will not have to pay sales tax. Shipping + tax can increase the cost from other suppliers by 15 - 40%, so compare delivered cost, not nominal price.

[4dks1]

Thank you Ben & Carl!

I ordered the K2006C test kit. It should arrive in 1 week. In the meantime it is very hot here. I have 11 gal 8.25% bleach. No tabs in floaters. Would you recommend having water tested at pool stores or add bleach & tabs until tester arrives?

From one of the other threads could you clarify running the pump & green water? Did it say don't run the pump if the water is green?

[PoolDoc]

If you can run the pump, but bypass the filter, do so. Live algae stops up DE filters almost instantly. You have to kill the algae before using the filter.

Can you get to a Sams Club and get 100# of dichlor?

There's really no point in adding bleach, till you have enough chlorine on hand to actually deal with the problem: 11 gallons of 8% bleach isn't going to touch what you need to clean up a 100,000 gallon pool. When I had to open neglected 'Olympic size' (75' long, actually, "Short course" pools) that were 120,000 to 200,000 gallons, I normally would add 110 gallons (2 drums) of FRESH 15% bleach.

If you add chlorine, without adding enough to do the job, you just end up wasting it.

[4dks1]

The local Sam's Club has dichlor. I'll pick it up later today. Do I just put it all at the deep end?

[PoolDoc]

Unpainted concrete -- yes. Any other surface -- scatter it. Even with concrete, don't just dump it all in one spot.

[4dks1]

The tool kit came early, so here's the readings before the dichlor was put in.
PH 8.0
TA 160ppm
CH 440
CYA 40ppm
FC 2
CC 2

Thank you!

[CarlD]

I'm a little leery to comment on such a big pool, but generally what these numbers mean is:

pH of 8.0 is too high and you should add Muriatic Acid to bring it down. I'd suggest to 7.0 or 7.1 because of the high TA level.

TA is 160 which for a concrete pool with a high pH and high CH level is too high. Therefore I'd suggest our ratcheting down method of lowering TA. Lower pH with acid which lowers TA as well, aerate to raise pH without re-raising TA. Repeat until TA is between 80 and 120.

CH is a bit too high -- 400 is generally the recommended upper limit for concrete pools. But with a few backwashes it will come down. Do NOT use Cal-Hypo anymore or add calcium since CH is 440.

CYA is generally fine at 40. FC should be maintained at 3-6ppm, shock at 15ppm

FC: too low
CC: too high.

Ben will give you better and more detailed recommendations and make any corrections he deems appropriate.

[PoolDoc]

The fact that you have CC=2.0 is not good.

You need add muriatic acid till the pH comes down. Read http://pool9.net/ma so you can handle it correctly and then add acid, a gallon at a time. Make sure the pump is on while you add the acid, and for at least 2 hours after. Continue to dose with gallon doses till the pH is 7.8 or below.

For a 100K gallon pool, with CC=2, dose with the dichlor at the rate of 1/2 gallon (about 5 pounds) at a time.

?'s:

1. What does the water look like? (clear/cloudy/opaque; blue/gray/greenish/dark green; odorless/chlorine smell/swamp smell
2. Are you running your pump 24/7?
3. Have you opened and cleaned the filter this season?
4. Can you purchase 100# drums of calcium hypochlorite?

Please explain these dimension:

Size 260"x260"x272" pool 96" spa

260" = 21' 8"
272" = 22' 8"

5. Are you saying your pool is a 22' cubic hole in the ground?

[CarlD]

This is why I said Ben is better with such giant pools than me. I'd never think to add Cal-Hypo to a pool with Calcium Hardness at 440ppm.

[4dks1]

Hi, this morning the pool is light green & milky. The 100# dichlor was scattered in before I got this post. 1 gal of muriatic acid was added last night. This is the lightest green the pool has been since last September!

Is there a way I could post a picture of the pool? It's very irregularly shaped.

Yes, the pump is running 24/7. The filter has been cleaned a number of times. It was back washed yesterday.

I will test the water again this evening & send the results.

[Watermom]

You can either use Picasa, Flickr, etc. to post your pic or email them to poolforum@gmail.com and include the thread number 116949.

[4dks1]

The pool smells like the ocean.

I emailed the pictures.

FC .6ppm
CC 1.2ppm
pH below 7.0
TA 80
CH 500ppm
CYA-I don't know if this is correct, I will retest.

[PoolDoc]

Definitely, do not add either baking soda or washing soda, with those values. If you raise the pH with washing soda (soda ash, sodium carbonate, pH Up, etc.) while having a CH=500, you're likely to precipitate calcium carbonate and make your pool look like milk.

You *can* use cal hypo, but add it via the skimmer after making SURE -- 100% sure -- that there is no feeder or gizmo anywhere between the skimmer and the filter. Also do NOT add CYA immediately after adding cal hypo, and do not add cal hypo within 3 days of adding CYA to the skimmer.

BUT . . . raise your pH, ASAP. You could use caustic soda, but that stuff is nasty to work with and usually expensive for consumers. Instead, go to Walmart and clean them out (up to 20 boxes): http://pool9.net/borax/ (Actual box is now mostly white, not green.)

Add boxes, 5 at a time, to your skimmer. Do it slowly, with the skimmer running. Do NOT choke the skimmer: borax can 'meld' together and form a solid, hard-to-dissolve, lump in your pipes if you do. Wait 4 hours to retest your pH.

[4dks1]

May 21 at 8:52 AM

ToThe PoolForum

Hi,

The CYA was way below the 100 mark. I tested it 3x. So I guess it's high.

The original owner of the house & the one who had the pool built told us it was 100,000 gals. The original filter was 90 until 2012 when this new one was bought.

Half of it is 8' deep & the other half is 5'. The push out area is 3' deep.

Here are the measurements just taken:
Length 48'1"
Width 40'2"

Thank you for your help.

[PoolDoc]

1. Retest CYA by mixing 1/4 cup of pool water with 3/4 cup tap water, and then testing the mix. Multiply your result x4.

2. Assuming a 'box' pool, with all right angles, and calculating 2 boxes, one 24 x 40 x 8 and one 24 x 40 x 5, you end up with ~90,000 gallons. But your pool is probably not a 'box', but is some sort of 'free-form' pool. And probably the transition from 8' to 5' is gradual, and is in the 'deep' section. Also, 5' water depth is VERY unusual, and is something I've never seen. I have seen 4.5' -- and people complained about it constantly.

If you can email your address to me, I'll take a look on Google maps, and see if I can do a better calculation. Another way to calculate volume is to carefully measure TA, add baking soda, wait 4 hours with pump ON, and then retest TA. 40# (you can get it as 8 -12 lb bags or boxes at Walmart or Sams) of soda should increase your TA about 30 ppm *IF* your volume is 90,000 gallons. If you add 40 lbs, and your TA increases MORE, than your volume is smaller.

Test TA accurately, add an exact amount of baking soda, wait, and test accurately again. Give me the EXACT numbers, and I'll recalculate volume.

Meanwhile, you need to be adding at least 5 gallons of PLAIN 8% bleach to your pool EVERY evening.

[4dks1]

For #1-CYA 140
For #2-What you said is correct.
For #3-I'll try that.

Here are the other results:
CYA 140
pH 7.5
FC .4ppm
CC .4ppm
TA 120ppm
CH 500

We've been adding the bleach.

Thank you.

[PoolDoc]

OK.

1. Definitely read http://pool9.net/cl-cya/; you will need much higher levels of chlorine than what you hve.

2. Tell me what sort of filter you have -- make/model. You're going to need to use either cal hypo or bleach to chlorinate. But you'll end up hauling a lot of bleach if you use that. You can use cal hypo IF you have a sand filter. It *MAY* be possible with other filters, but I haven't personally tested that, so you'll have to do so VERY carefully if you try that.

3. Check on your options for purchasing bleach. Can you buy 12 - 15% commercial bleach (aka 'liquid chlorine') in 2 - 5 gallon containers?

[4dks1]

DE filter Pentair Fns plus

Bought 12% Liquid chlorine & added 8 gals. Will look for 2-5 gal containers.

[PoolDoc]

See if you can buy -- and transport -- 100# containers of cal hypo locally. You're looking for prices of $2.75/lb or less.

You could also see what it will cost to have Leslies or one of the other online consumer chemical companies deliver it to you.

But . . . you'll need to comfortable monitoring your chemistry with a K2006 to pursue this. I've successfully used cal hypo on multiple occasions in large commercial pools, without having problems with calcium build up or pH. But it will be an off-label application method.

Also, you will have to be able to periodically backwash, or else open and wash out, your filter to use this method.

[4dks1]

I was able to find cal hypo. Questions before I use it.

Pool still green & not clear. Also found small possum in skimmer outlet. If I understand correctly we don't want to use dichlor right now to keep it balanced, that's why we need cal hypo?

We're using 12% liquid chlorine, but the cal hypo will clear it faster?

Using the Barracuda is not harmful is it?

Thank you.

[PoolDoc]

1. Your CYA is VERY high, so you don't want to add more. That fact rules out use of trichlor (pucks) and dichlor (granules).

2. Cal hypo can help the water clear faster, with sand filters. It's not going to help as much with a DE filter, unless you are trying to remove metals. But it can still be used OK.

3. Use up your bleach, first. It's perishable. You want to reach FC levels of 20 ppm or HIGHER.

4. Cal hypo needs to be added DIRECTLY to the skimmer, but FIRST you have to make sure there are no devices or feeders ANYWHERE between the skimmer and the filter. Cal hypo and dichlor / trichlor react badly if they come into direct contact with each other.

5. Once you began using cal hypo, you need to let your pH 'float' unless the level exceeds 8.0. If you add via the skimmer, and let the pH float, your TA and CH levels will not get too high. If you add cal hypo directly to the pool OR try to adjust the pH down, your TA and CH levels WILL get too high, from the cal hypo.

6. Please complete the form here: http://pool9.net/pf-chart/ with the most current info you have on your pool's dimensions and equipment.

[4dks1]

The pressure seems to rise quickly resulting in lots of backwashing. Is that normal when you're trying to get clear pool water?


FC .2
CC 1.2
pH 7.4
TA 150
CH 300
CYA unable to determine

++after grid & manifold replacements. 25lbs of Cal hypo added.
DE filter

[PoolDoc]

I checked your entry in the equipment spread sheet. Is your pool really 260 inches (21.7') by 260 inches square? That's what you entered.

Your chlorine is too low -- you will get algae quickly, like that.

Why couldn't you determine your CYA? Did the mixture remain clear? If so, that means your CYA = 0 ppm.

[4dks1]

Pool length 48'1". Width 40'2". 8' deep down to 5'. Shallow end 3'.

Cya must be 0 then. Mixture remained clear.

Adding liquid chlorine 10-12% every other day. 6-12gals but FC still very low.

[PoolDoc]

1. Go to Sams Club and buy (2) 50# buckets of dichlor (~$240). Get a trial membership if you need to do so. Given the amount of dichlor you'll need, a Sams membership will be worth it for you. Together, those will add about 80 ppm of chlorine, and about 70 ppm of stabilizer to your pool.

2. Set your pump timer to run 24/7. Your pump and filter are too small for your pool, and you'll need to run more to make up. Once you've got everything straight, you may be able to switch to low speed.

Get the dichlor from Sams, ASAP. But if you can't do so immediately, add nightly doses of 6 pounds of cal hypo OR 5 gallons of PLAIN 8% household bleach. Do this EVERY evening. Add the doses ONLY in the late evening. If -- and only if -- your pool is crystal clear and algae free, you can cut those doses in 1/2.

Each time the pool is used by a swimmer, add 1 pound or 1 gallon of bleach during or immediately after their swim.

I'm reluctant to encourage you to use "liquid chlorine" (commercial bleach). It's hot summer, and bleach loses strength rapidly, unless it's stored cool (75 degrees or LESS). If you are buying boxed pool bleach, odds are you are NOT getting 10% bleach.

You can compare, though. Add 4 gallons of 10% bleach; test chlorine levels 2 hours later. Tomorrow, add 5 gallons of Walmart 8% bleach, test chlorine 2 hours later. If your 10% bleach is REALLY 10%, you'll see similar FC levels from both.

But maybe not. Your CC level above (1.2 ppm) suggests you've still got goo in the water. If so, to compare the bleach and the LC, you'll need to go for 4 consecutive nights: bleach, LC, LC, bleach, and then average the results for both the bleach and the LC before comparing. Make SURE you add all doses at about the same time each day, LATE in the day.

[4dks1]

I have the 100# of dichlor from Sam's to put in tonight.

Thank you.

[PoolDoc]

You're welcome.

Please note that I was NOT suggesting that you add it all at once; rather that 100# of dichlor was an appropriate quantity for your pool, and will allow you to raise your stabilizer in the process of chlorinating.

[PoolDoc]

Per your email, you should vacuum up all that loose DE.

(BTW, please post online instead of emailing. Thanks!)

[4dks1]

Oh, sorry about that. Here's the post:

Before the grids & manifold were replaced, it seems that the filter was blowing DE powder back into the pool. I'm guessing that's why it's still cloudy, that there's lots of DE powder in the pool. Although, I can see the step now in the deep end!



Per your email, you should vacuum up all that loose DE.

Does the DE powder settle to the bottom of the pool or is it suspended in the water causing the cloudy water?

[PoolDoc]

The DE settles, the dirt that was in the DE is likely suspended.

[4dks1]

New readings
FC. 5.4ppm
CC 2.4ppm
pH 7.0
TA. 150ppm
CH. 440ppm
CYA 50 ppm

Yeah, there is finally FC!

[PoolDoc]

1. Are you testing with the K2006?

2. What does your water LOOK like? (Please fill out this form: http://pool9.net/pf-hist-form/)

3. Can you verify that your pool has NO feeders or chemicals anywhere between the skimmer and the filter?

4. How much dichlor have you added?

[4dks1]

1. Are you testing with the K2006?
Yes.


2. What does your water LOOK like? (Please fill out this form: http://pool9.net/pf-hist-form/)
Cloudy, light green


3. Can you verify that your pool has NO feeders or chemicals anywhere between the skimmer and the filter?
No feeders or chemicals between skimmer & filter..


4. How much dichlor have you added?
40#

[PoolDoc]

Add 15 pound doses of cal hypo THROUGH THE SKIMMER.

If you mix some DE in as you add the cal hypo, your filter won't stop up so quickly. But doing this will result in calcium depositing on the filter. You'll need to manually clean the filter at least every other time, even if you have a multiport valve.

Do NOT adjust your pH down, unless it goes above 8.0. It must 'float'. Doing it this way will prevent the cal hypo from adding extra calcium to the pool; it may even lower the calcium and/or alkalinity in your water.

Do NOT ever allow cal hypo and dichlor to come into direct contact with each other. They are fine, once they've been dissolved, but BAD things will happen if they touch each other as solids!

[4dks1]

Added the 15 lbs of Cal hypo. Is this to be done until the water clears?

Thank you for the DE powder tip.

Keeping the Cal hypo & dichlor separated. I appreciate the warning.

[PoolDoc]

Yes.

But you need to understand that you can expect to loose 15 ppm of FC weekly -- on your pool that translates into 15 pounds of cal hypo weekly . . . when everything is perfect.

[4dks1]

What parameters are we looking for to be able to swim in the pool? It is not clear at the bottom of the deep end yet.

It's looking so much better, thank you so much!

[PoolDoc]

Chlorine = to 10% of CYA level; pH between 7.0 and 8.0; no slime.

[BigDave]

Also be concerned with cloudy water. If you can't see a swimmer on the bottom, you can't rescue him.

[4dks1]

Ok, thanks.

[4dks1]

My pool is clear!


Thank you, thank you!

To make sure it stays clear, please clarify what we need to do from this point. We have Cal-hypo and dichlor
We're adding a gallon of 8% bleach after swimmers.

[PoolDoc]

Looking at these results:

7/27/2014 18:30:00 32 psi
K2006: 10.2, 1.0, 7.5, 140, 430,30
blue crystal clear No odor No algae crisp, clean
Brushed pool, Vacuumed pool, Cleaned filter, Added chemicals

It looks like your water is in excellent shape, so:

1. Maintain 2 - 5 ppm of FC

2. Cal hypo is fine, but ONLY if you add it via the skimmer. Also, if you use cal hypo, you must let the pH 'float', unless it goes above 8.0

3. Your CYA is low enough, so that you can also use trichlor. You might want to use trichlor in a floater, to maintain a constant feed, and dose with cal hypo in the evenings to boost chlorine levels.


Note that trichlor and cal hypo must NEVER come into direct contact.

4. You asked about paying -- if you'd like to do so, we'd certainly welcome a subscription: http://pool9.net/subscribe/

Thanks!