removing the cloud

[essikr]

23,000 vinyle liner been using BBB method for over 20 years .This is the fist time I have had cloudy water. Went away for a week ,before leaving made sure the chems were up.The water has been clear all summer.Lots of rain while we were gone. Came home to a cloudy pool,0 chlor,7.0 ph,50 alk. So far I have put 6 gallons of 15% liquid in. At 4 it only raised it to .5.After 6 it went to 3.0,Ph still at 7.0 (did add abox of Borax) Alk at 50. I put one more in just now ,plan on running the DE filter all night:(. I did backwash and replace DE before adding the Chlor. The CYA is at 70. Is there anything else I need to do. I will do a test in the morning and post the results.

[Watermom]

With a CYA of 70, you must keep your chlorine between 5-10 all the time. If it dips below 5, you risk an algae bloom which is probably the reason for your cloudy water. You need to shock your pool, which with a CYA of 70 is up to 20ppm. (Take a look at the Best Guess Chlorine Chart in my signature below.)

Is your volume really 2300 gallons or did you mean 23,000 gallons?

[essikr]

Thank you for the input.I'm sure you are right about the algae bloom and knew it was 23,000 my fault. Test this morning Chlor 4.0 ,PH still at 7.0. I will put more chlor in till I get to 20ppm and keep the level at 10 ppm.
WOW,that means I will have put in 12 gallons of 15% liquid to get the pool up to shock level. Lucky, to have a store close that had the 15% at $3.49 a gallon.
To all of you out there ,don't let this happen to your pool.If your going away and leaving the pool unattented,make sure it's up to shock level before leaving.

[Watermom]

NO, NO, NO! WAY too much! A gallon of 15% sodium hypochlorite will add 6.5ppm of chlorine. Adding 12 gallons of it will add 78ppm of chlorine! Way too high! I hope you haven't done it yet. (Hopefully, it is has degrades and is nowhere near the 15% it is advertised to be.) Where did you get that amount to add?

[essikr]

The level I'm reading with my K-2006 test kit says the chlor level was at 5ppm after adding 10 gallons. This what I have added so far.The water is clear and looks just fine.
2 gallons = trace
4 gallons = .5
8 gallons = 4.0
10 gallons = 5.0 thats what is testing at this morning using the kit with the DPD powder
with a 10ml sample it took 10 drops fas-dpd titrating reagent to be clear.
Can i trust the test kit.The powder was new at the beginning of the season.Is there anyway to test the actual strength of the liquid chlorine? The jug says extreme pool shock available chlorine 15% ,sodium hypochlorite 12.5%,inert ingredents 87.5%.
I had fiqured that 1 gallon would raise it 5 points,That doesn't seem to be happening,is it the test kit,the chlorine or is the algae that was going to bloom eating up the chlorine. I have had seen some algae over the years but in over 20+ years never had cloudy water problem like this.I appreciate your help, thanks.

[aylad]

Here is the method that was posted long ago by another mod, CarlD, for checking the strength of your chlorine..
(Begin copied material)
Put ten liters of tap water ( That's 5 soda-bottles full) in a 5 gallon bucket.

Test that water for chlorine using the FAS-DPD test to get a chlorine baseline (you may have some).

Then I take a 1 ml eyedropper full of the LC or bleach I'm testing and put it in the bucket and mix it up.

(1 ml in 10 liters of water is the same as putting 1 gallon of LC in a 10,000 gallon pool -- it's 1/10,000th. )

I then measure the bucket with the FAS-DPD test just like pool water. Of course, subtract any chlorine you measured in the tap water.

(End copied material)

One gallon of 12.5% chlorine should add 5.4 ppm of chlorine to 23K gallons. It is possible that the chlorine is being eaten up by algae, but not at that rate. 10 gallons should add around 54 ppm, and if you can't see visible algae in the water, there's no way it's eating up 49 ppm of chlorine before you can measure it. Any chance there's ammonia in the water, or hvae you added polyquat or something else that can create such a big demand?

[BigDave]

Does the pool have a strong "chlorine" smell? Have you lost any CYA?

There've been a couple posters on the forum this summer (and many in the spring) that had CYA to ammonia conversion in a very short time in an unkept pool. This would create a large chlorine demand.

[essikr]

It's nice to have this support ,thanks. I tested the chlorine and it was higher than 5.4 but I may have used more than 1ml. So the chlorine is good and the test kit must be OK. Just did a water test,there is no chlorine smell but I did see a trace of algae near the step.The water is clear. Do I need to put more liquid in???
Chlor = 4.0 (was 5.0 yesterday)
PH = 7.2 added box of Borax
CYA = 60 (it was at 70)

[aylad]

You need to get it up to shock level and hold it there until the water clears and until the algae is gone. You'll know when it's time to let it drift back down when you can measure chlorine at night and in the morning before the sun is on the pool, and not have more than a 1 ppm drop between the two measurements.

[PoolDoc]

The level I'm reading with my K-2006 test kit says the chlor level was at 5ppm after adding 10 gallons. This what I have added so far.The water is clear and looks just fine.
2 gallons = trace
4 gallons = .5
8 gallons = 4.0
10 gallons = 5.0 that's what is testing at this morning using the kit with the DPD powder with a 10ml sample it took 10 drops fas-dpd titrating reagent to be clear.
Is there anyway to test the actual strength of the liquid chlorine? The jug says extreme pool shock available chlorine 15% ,sodium hypochlorite 12.5%,inert ingredients 87.5%.

You pretty much did a test that indicates your "extreme pool shock" is anything but -- it probably cooked off this summer in somebody's warehouse.

It is possible that something else is happening, however. Do this:

1. Add 4 gallons of freshly purchased PLAIN 6% Walmart bleach in the evening. Make sure the pump is running.
2. Test for BOTH free chlorine and combined chlorine after 30 minutes.
3. Test for BOTH free chlorine and combined chlorine again, in the morning.

Also, test for CYA in the morning, and tell us how that reading compares to what you had seen earlier this summer.