Heavy Chlorine Demand - was told to drain pool!

May 30, 2010
5
This is only our 2nd season with a 22,500 gallon inground pool - we thought to play it safe and have a pool service help open and balance our pool by Memorial Day. I knew things were going wrong when the pool was green and getting worse about 1.5 weeks ago. I kept asking for a chlorine demand test. They never did it, so yesterday I brought my water in for a chlorine demand test and they told me to drain and refill the pool 2x because it was a lost cause - I have ammonia in the pool and they talked about phosphates! Although as of 7 days ago the pool was clearing up - AND yesterday it was actually fairly clear. The other alternative they gave me was buying 130 bags of Burn Out for over 1000K!

Instead I found your website and spent 4 hours studying it last nite. I have 3 different brands of bad test strips AND some OTO along with Phenol Red to do better testing of the chlorine levels and Ph. (Yes, last nite I bought one of the recommended testing kits, but can you help me before my equipment completely is corrupted?) My recommended pressure for my sand filter is supposed to remain between 14-15...BUT, after only a few days of circulating 24/7 the pressure goes up to 18-20...I backwash and the water is dirty - definitely affecting pressure. (I know how to backwash and rinse...). But, there's a problem here, just changed the sand completely in March 2009.

My reading per the weak test strips and OTO/Phenol drops (I've used all 3 to try and make sure it's at least close) is:
**Bromine (I NEVER added it - just shows up on strips) @3
**This AM Free Chlorine at 0 (per the strips) - BUT per the OTO test (where I add the drops) - @ 1
**LAST NITE at midnight (after studying your website for HOURS - and adding 364 oz. of 10% bleach) the test strips showed .5 - 1 for Free Chlorine and the OTO test was still @ 1
**This AM Ph per the test strip @ 6.8 - BUT per the phenol drops 7.2
**LAST NITE at midnight (before adding 375 oz of Borax) 6.2
**Total Alkalinity (per test strips - I've orded the recommended testing kit!) is @130-150 ppm
**Total Hardness 100ppm
**LAST NITE Cyanuric Acid per the test strips below 30 (between 0 - 30)
**This AM Cyanuric Acid seems to be at 30 (how could this be?)

I added the Borax 2 hours before adding the Bleach...to make sure I brought the Ph up enough...the Ph was ridiculously low -- and although the 'pool guys' kept giving me balance pak 200 it did absolutely nothing. Smaller amounts of Borax from last nite brought this up more than the expensive stuff.

Didn't know to clean my sand filter until researching things yesterday - So yesterday purchased a bottle of a cleaner and added it to the skimmer (per directions - during backwash).

What should I do next? Please help. DON't WANT to DRAIN MY POOL or spend 1000K on burn out! :shock: :shock:
 
Well test strips are historically inaccurate so I would not put any faith in what you are seeing there. So you say you DID order a good test kit and said you read the Pool School articles? If you didn't order a GOOD test kit, please do so - you can't know for sure what you are dealing with using strips. Can you bring your water sample into a pool store locally until you get your test kit?

If your pool is still showing signs of contamination, you will need to continue to add enough chlorine to keep it at shock level long enough to kill off the algae along with the brushing and backwashing to clear your pool. This has to be continued for regular intervals until your pool holds a free chlorine level over night.

I'm not sure what kind of "cleaner" you were advised to buy for your sand filter. I guess I have never added anything to my sand filter to clean it - simply backwash and rinse with enough chlorine in my system to kill the algae and organics both in pool and through the plumbing. I have added some sand at start up after a number of years - your sand is new so adding shouldn't be required yet.

I wouldn't add any of the stuff the Pool Guy gave you - not sure exactly what is in it and what it will do to the chemistry. Get your PH 7.2-7.6, you need to get a good test that accurately shows CYA levels and get it to that 40ppm level if it is not there.
 
Welcome to TFP!

You don't need to drain your pool and you don't need to waste your money on Burn Out. You will, however, need lots of bleach because with ammonia in the pool, it's going to take lots of shocking to clear it.

It will be tough for you to shock and clear your pool until you have the proper test kit to accurately test the levels. Since you have ordered it though, it will arrive fairly quickly and you can get to work on things. The main thing about shocking is that you want to maintain the shock level of FC in your pool and this is going to be a higher level than you can accurately test for with the simple kit that you currently have. Best to wait until your good kit gets here.

Ignore phosphate readings. This is a sales tactic and nothing more than that.
 
My humble opinion:

Keep filtering, keep brushing, and read through Pool Schoolagain and again until a proper test kit arrives. Toss the other test kits when it arrives. If you must do something, take a sample to the pool store and have them get the copper levels - who knows what the PB has been putting in? Start amassing huge quantities of pool chlorine or bleach.

When the kit arrives, measure CYA. Decide then if you need to drain. Don't get impatient and get the CYA reading from the pool store. It will be wrong. And they're persuasive salesmen, you may walk out with hundreds of dollars of junk. If CYA is at some reasonable level (post the results here and we'll tell you) then get the pH adjusted and shock, shock,shock. When you have clear water, fine tune the rest.

Phosphates are immaterial. I haven't a clue what mine are, none whatsoever, and my pool is so clear I can tell that the screws on the spa drain are phillips head, standing on the deck!
 
Took my water in (NOT to the place that initially helped me open this year). Here's what the readings came back in as (no test strips used - which I realize now are worthless).

Free Chlorine - 3.1 ppm
Total Chlorine - 7.3 ppm
Combined Chlorine - 4.2 ppm
pH - 7.1 (thank you everyone ! granted I added Borax somewhat blind but I'm in a safer range! - Who knows where I was before!)
Hardness - 70 ppm
Alkalinity - 120 ppm
Cyanuric Acid - 75 ppm


Total gallons for my pool are actually 24500.
Pool Type - Vinyl
Filter - Sand

I know I need to Add Bleach like crazy but...shouldn't the pH and Hardness be brought up? or is it necessary?
 
I know I need to Add Bleach like crazy but...shouldn't the pH and Hardness be brought up? or is it necessary?
Your pH and hardness are fine for now. disregard them until much later.

I would....

1. Reduce CYA to around 40-50. You will need to drain and refill approximately 1/3 to 1/2 of your pool to do this......there is no other way.

2. After your CYA is down to a manageable level (40-50), then you are ready for massive doses of chlorine. I would suggest buying 30-50 gallons of bleach. You will use it all this summer if you don't use it all clearing your pool.

3. In Pool School, read "How to Shock Your Pool" and "ABC's of Pool Water Chemistry". Get your pool sparkling clear through the shock process and then we'll help you fine tune it so it'll stay that way.
 
Hardness isn't an issue in a vinyl pool. You can leave the PH alone for now and deal with it after you are done shocking. There instructions in "further reading" in Pool School on how to do a 'bucket test' to determine extreme chlorine demand. It will take an awful lot of liquid chlorine to oxidize the ammonia and high CCs. Just have some POP while you wait for your kit and keep the FC up to shock level.

I'd seriously consider draining down to the bottom of the skimmer and refilling to try to lower the CYA level - trying to shock with your CYA at 75 will be difficult. If you lower the CYA level you will need less clorine to reach shock level - refer to the CYA chart.
 
I had this problem last year.

Go to a pet store and buy an ammonia test kit. You will get a sense of how much ammonia is in there.

Next, get a lot of bleach and start adding until the ammonia is gone. Ammonia and chlorine cancel each other out so just keep adding bleach. I used 30 gallons of 12% from the pool store to clear up my pool. I also ended up refilling 1/3 of the water to make the process more manageable.

Going to the pool store for advice was a painful mistake. I found the BBB method here and everything is good.
 
I'll add just a couple things to what other people have said.

The OTO test measures TC, it can't distinguish FC/CC. (TC = FC + CC.) If you start shocking before the big kit arrives, I suggest this: First, use the Pool Calculator to figure out how much bleach to add to bring TC up to 26. Add that bleach, give it 1/2 hour to circulate, then do the OTO test. It will be some kind of orange/red/brown color. There's no color block for this, you just have to remember what it looks like. That's your target, until the big test kit shows up. You'll just be guessing about bleach amounts until then, but the OTO can at least give you a hint.

Also, ignore the pH while you're shocking, it starts to flake out as TC goes above 10.
--paulr
 
As others have said you need to drain some water and replace to lower your CYA levels, I would suggest getting some use out of the draining and doing it while you are using the pool vac to carry off some of the stuff that is growing in the pool, also your not going to hurt anything by semi-blindly dumping bleach in (a few gallons per day) until your test kit arrives, just don't go too overboard (unlikely), it may not make things much better, but it will at least keep the stuff growing in your pool in check, and if you do get it to shock level you may be able to keep it there long enough to do some good, after all bleach is cheap, even if you dump 10-15 gallons in while waiting on your test kit, that is likely only $20-30.
 

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Hi deepwater,

If someone told me I needed 130 bags of burn out at $1000 :shock: :hammer: :hammer:

You are doing a very good job reading and getting a handle on things and have gottten great advice.

Some pet stores do a free ammonia water test. Walmart also sells an inexpensive ammonia kit in the pet department.

When you get a moment, please add your pool and equipment specs in your signature.
Go to User Control Panel (upper left under TFP logo) & select Profile, then Edit Sig.
This will be very helpful to those responding to questions.

Welcome to the forum :wave:
 
Got My kit still having problems with chlorine demand!

Topics Merged for Consistency

As of June 3, 2010 -

Combined Chlorine - 8.0
Free Chlorine - 0.5
Total Chlorine - 8.5
CYA - 110
Total Alk. - 170
Borates 30
pH - 7.2


As of this AM June 4, 2010
Free Chlorine - 0.5
Combined Chlorine 8.5
Total Chlorine - 9.0

Please help...what to do next? I was the one told to drain my pool because of ammonia.

Using my new TRTestkit. Thank you.
 
You do need to drain some water to decrease the CYA levels. But, dont drain the whole pool. Since you have a vinyl liner, draining the entire pool would cause the liner to float and you would have to have it re-set.

As was suggested above, get a ammonia test kit and see how much is actually in the pool. From that number, we can tell how much chlorine (ballpark) it might take to clean it up.
 
You are looking to drain around half the water, trying to lower your CYA 110 to more like 50-60. With a vinyl liner, you can safely drain down until you have about 1' left in the shallow end; more than that and you risk the liner shifting. In many IG pools that is about half the total volume.

Note that the CYA could easily be higher, as the usual test can't really distinguish levels above 100. But we'll cross that bridge when we come to it.

If you are goig to drain, do that first, because otherwise you are spending money treating water that you then throw away.
--paulr
 
I drained 1/3 of the pool...refilled with water...it rained 1 inch, so I had to drain 1 additional inch.

I've been adding 12% liquid shock ....4 cases on Saturday....non chlorine shock yesterday (3 lbs)....today I added 4 lbs.

CYA - 60 ppm (the home test is very difficult to get an actual read on)...I took in a water sample to make sure the reading was correct and it correlated to 60ppm

pH - 7.4

Free Chlorine - finally turned this AM after the 4 lbs of non chlorine shock - 2ppm (was only .1ppm)

Combined Chlorine - still at 5 ppm (although down from 6.9ppm)

Alkalinity - 120

How do I maintain the shock level - from what I understand this needs to be maintained, but I don't know for how long.

Additionally I have a chlorinator and just refilled with 6 (3inch pucks) on Saturday - because of how much shock and combined chlorine I had in the pool I turned down my chlorinator to 4 (out of 9)....however, as of this AM - the pucks are almost completely dissolved...do I potentially have a problem with my chlorinator?

Checked my sand filter to make sure no problems there...still very fine...water can pass through easily.

Suggestions?
 
deepwater01 said:
How do I maintain the shock level - from what I understand this needs to be maintained, but I don't know for how long. You add enough chlorine (preferably liquid chlorine or bleach according to the pool calculator to reach shock level. Then retest in 30-60 minutes to see if you are there. If not, add from that number to your target shock. You just keep testing and adding testing and adding...until the shock complete in pool school criteria are met.

Additionally I have a chlorinator and just refilled with 6 (3inch pucks) on Saturday - because of how much shock and combined chlorine I had in the pool I turned down my chlorinator to 4 (out of 9)....however, as of this AM - the pucks are almost completely dissolved...do I potentially have a problem with my chlorinator? No. You just drained a third of your pool because of high CYA. Those pucks just raised it again. Please cease using the pucks.

Checked my sand filter to make sure no problems there...still very fine...water can pass through easily.

Suggestions?
Just keep shocking.
 
Given a CYA of 60, your "shock" FC target is 20 ppm and your min/max FC are 5 and 10 ppm.

You should dose your pool to maintain the FC at 20 ppm until your night FC and morning FC (overnight demand) are the same number. Remember, that FC is broken down by the sun. So, if we measure it overnight and there is a chlorine loss, that means that something (organics, etc) is consuming your chlorine.

The only chemicals you should add to your pool are bleach (free chlorine), baking soda (to raise alkalinity), borax (to raise pH) and muriatic acid (to lower pH). Please stop using everything else.

Your other numbers are fine for now....just add bleach several times daily to keep your FC at 20 until it is 20 in the am for a day or 2...then let it drop between 10 and 5 (but never under 5) given your high CYA level.
 

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