Trouble holding chlorine

[rwhession]

Looking for advice regarding my difficulty establishing initial chlorine levels. We opened 8 days ago and the water now appears sparkling clear. Easiest clean up ever (2 days from black/green) to present state, but no matter how much shock (liquid bleach) added, it is gone within 20 minutes.

Here are present results: temp 74, sat index-o, TDS- 1000, CYA 24 (adding 3.5 more lbs stabilizer as I wrtie), TC 0.03, FC 0, Ph- 7.5 TA 131, Adj TA 124
Total hrd- 206.

This is a 20X40 vinyl lined pool with DE filter
Pump running fine, at about 10- 12

Again, visual is perfect. Crystal clear...
We are leaving for a week long vacation next Wed. (7/13), so I am anxious to remedy.
Also interested in the "what if..." (if pool is in present state, any thoughts on vacation treatment? I will have another pool owner looking is.)
Thanks -- this is my first post. Appreciate your patience and advice.

 

[JohnT]

Welcome to TFP!

How are you testing, and how much are you adding?

Some test methods are subject to bleaching when chlorine levels are high, so it pays to have multiple test methods available.

 

[rwhession]

had pool store test to get complee readings

 

[Bama Rambler]

Pool Store tests have the same problems.

Do you have a OTO chlorine test kit? That's the test kit with the yellow side for chlorine and the red side for pH.

If so use it and let us know if it gets yellow.

I strongly suggest you order your own good test kit. That way you won't be relying on somebody else who doesn't care about your pool.

 

[Ohm_Boy]

Some simplifications...
Two things will make chlorine "go away".
- 1) UV radiation, always an issue in the sun.
- 2) Organic 'things' in the water which the chlorine is trying to destroy. This is also the only way to lose chlorine at night, hence the Overnight Chlorine Loss Test, discussed in various places on this forum.

If your chlorine isn't reading after addition, then either
- 1) your reading is faulty,
- 2) your chlorine is being consumed (see above), or
- 3) you're not really adding chlorine. (check for weak/old bleach, acid instead of in your 'bleach' bottle, DE powder instead of dichlor, etc.)


Focus on those, you'll find your problem.

 

[rwhession]

readings are the same on my home test kit and pool store tests.

I will order my own advanced test kit, as advised. I know there was a resource posted here. Will get on that.

Would anyone suggest going back to powdered shock? (I used 1 1/2 cases during the first 5 days; once clear, I converted to liquid as I was under the impression liquid is preferred. I have been using 6% store brand and / or chlorox. Have added 38 bottles over the last 4 days.

My pool is in full sun. We run the filter 12-15 hours a day (after 24/day until clear) and use a robot to mix the water, as well as clear minor debris, daily. I have been brushing non stop. No visible algae of any kind. Initial treatment (Banish) did the job on opening algae, and I have used Back-Up maintenance dose, once.

I have 7 more days here at home to oversee, then leaving for one week vacation! Yikes! As I close in on departure, I will seek advice based on the situation at that time. I did add 4 more lbs stabilizer today...

Last year, once we got balanced, I converted to BBB method with OUTSTANDING results and clarity as never before...
Thank you, all.

 

[Bama Rambler]

You've added 54 ppm of stabilizer not counting what the shock was putting in there if it was Dichlor. It could be much higher than that.

You says the water is clear but are you still losing all the chlorine immediately after adding it? Are you using the OTO kit to test it?

 

[rwhession]

yes, no chlorine registers approx 20 minutes after each "shock" (ranging 3 bottles to nine bottles...)
I do have bioguard silk sticks in the skimmer baskets, as well.

 

[Bama Rambler]

You might consider picking up an ammonia test kit and see if any registers on it. That would explain your high chlorine demand.

 

[Kimmisue]

If it's ammonia, how do you fight that? (Sorry to butt in.....just trying to learn)

 

[Bama Rambler]

It just takes a lot of chlorine. A LOT of chlorine!

 

[retrodog]

I have a similar problem. I can't get my chlorine level up. I've even got 3" tablets laying in the waterfall in addition to my chlorinator. They are all desolving at a historically normal rate but I still have almost no FC and little CC when I check it. I've also been pouring Chlorox in to keep the water pretty.

I think I'm going to put a bunch of tablets in a bag and hang the thing right in front of one of my return jets.

Where's all my chlorine going?

 

[Bama Rambler]

It's being consummed by something and you need to find out what that something is.

 

[retrodog]

It's being consummed by something and you need to find out what that something is.

Ok, I guess I'll get an ammonia test kit. What else could be using it up like that?

My current test kit is the OTO type that you describe. And I also have a CYA test kit that shows my stabilizer being very very very low.

The guy at the pool store checked my water and gave me a printout. He said it looks just fine with the exception of having almost no chlorine in it.

 

[retrodog]

Now that I think about it, what would cause ammonia to exist in any quantity other than people peeing in it? I ask because no one has been peeing in my pool and it's about 30,000 gallons. Is there some other source for ammonia, or is there something else that could be burning off my chlorine?

 

[JasonLion]

Ammonia can come from fertilizer getting blown into the pool, or from the breakdown of CYA over the winter.

It is almost certainly ammonia. We get lots of these in the spring when more people are opening their pools. Testing the ammonia level can give you a hint to how much chlorine you are going to need. It is also possible to do an extreme chlorine demand test to measure the same thing. However, there is no real need to test the ammonia level. The end result will be the same, it will take the amount of chlorine that it takes. There is real need to know that number in advance, though it can be comforting.

In any case, the thing to do is to continue shocking the pool, as described in Pool School. In this situation you only need to add chlorine once a day, but adding chlorine more frequently than that will resolve the problem more quickly.

 

[rwhession]

just want to thank everyone for their thoughts... I think the fact that it is soooo clear and beautiful (visually) makes the problem seem less daunting. I will keep testing and keep adding chlorine.

 

[Bama Rambler]

At some point you'll start gaining on it and then the FC will start holding. Just keep after it.

 

[rwhession]

resolved!
after a significant rain, causing me to drain some water, back wash and add 3 lbs of stabilizer, we are holding! Not sure which variable turned the page, but!
thank you, everyone for your input.

 

[Ohm_Boy]

Yay!