New Pool Owner, Losing A lot of Chlorine

Jump to latest Follow Reply
S

schilsky

0
Apr 9, 2015
6
Dallas/Ft. Worth
HI All,

First off, thanks to everyone who contributes to this site. It has been extremely helpful as begin to figure things out with our new home and the pool it came with.

The pool is pretty clean looking, clear water and nothing visibly wrong. I took apart and thoroughly cleaned the DE filter and the grids. It was pretty nasty and there were some small areas of visible green algae starting to form. Nothing overwhelming but present in areas. Now that it is clean, the pressure is in the 12 -13 range which looks to be normal based on markings by previous owner.

My next step has been to try and balance the water. It has an in-line chlorinator (3" pucks) but after what I have read here, I am thinking to avoid the "shock" and puck products and go with liquid bleach from Costco. I have been having a **** of a time keeping chlorine in the pool which led me to believe something is hiding and growing somewhere and eating the chlorine. I got the chlorine levels up to ~22 or shock level (given CYA 75-80) only to see it drop off to around about 24 hrs later. My CC was 0.5 so I didn't expect a huge drop like this.
I decided last night to and hit it hard and start officially a SLAM process and brought the chlorine level to 25ppm (around 8pm last night). I woke up this morning and measured only 11ppm chlorine. For such a clean looking pool, this seems extreme.
I again put more bleach in this morning to bring it back up to around 24.5 and will check again in another hour or so to see where I am at.

My CYA is between 75-80, pH around 7.5, and TA around 100.

Is this much overnight chlorine loss abnormal for a pool with what I thought was a minimal issue?

Thanks again for all the advice.
 
:wave: Welcome to TFP!!!

Well you are almost on the right track. You certainly need to follow the ShockLevelAndMAINTAIN Process, but you are not raising your FC high enough. For a CYA of 80ppm, shock level is a FC of 31ppm according to the FC/CYA Chart and PoolMath.

Pools can be deceptive. Even though clear, there must be something lurking in the water.

- - - Updated - - -

Please add a little more info to your location in your profile ... I have no idea where Southlake is.
 
What you're describing is not unheard of.

In fact, I'd venture to guess that if your pool has been fed a steady diet of pucks, your CYA should be higher than 80. If it's not, maybe some of it decomposed into ammonia. Ammonia is a voracious chlorine consumer. It will neutralize bleach almost as fast as you can pour it in. Since the CC is low, you're probably through the worst of it. Take it up to shock level and brush everything. Don't neglect light fixtures and ladders and inside the skimmer throat.
 
Thanks for the quick responses. Not sure why my first calc on SLAM level was lower but I will bring it up to the 31ppm level.

I brushed the tile at the water line over the weekend and there was some small areas of algae, as well as the skimmer throat. Hoping I got most of that taken care of. I am thinking I need to pull the light fixtures from the wall as one of them has water in it and needs replaced. No ladders in this pool.

Thanks for your advice!
 
Hi, if your CC is really only .5 then its probably not ammonia... but I agree with the above that you probably haven't shocked high enough and you have something "unseen" lurking. Follow the SLAM process to the T. What are you testing with?
 
Update:

I took the FC levels up to 34ppm at 11:45am. By 2pm, the level had dropped to 27.5ppm. Loss of 6.5ppm in just over 2hrs - mostly in sun with pump running.
I added 2 jugs of Clorox 121oz 8.25% to bring it up to around 34.5ppm. I will re-check here in about 2 hours to see how its doing.

Note to self, buy stock in Costco and Clorox.
 
Quick question. As I am working through the SLAM process, do I need to be backwashing the filter at all? Pressure has not risen much at all, but not sure if it should be done regardless.

Pool is looking good, clear water but still lost about 9-10ppm of chlorine last night (from 34ppm to about 24.5ppm this morning). I took the levels back up to 35ppm this morning and will retest in an hour or so. I pulled the pool light fixture out last night as well, and did notice some small green areas around the ring of the light.

Is there a typical (I am guessing nothing is typical when it comes to pools) time frame it takes to eliminate the overnight chlorine loss?
 
schilsky said:
Quick question. As I am working through the SLAM process, do I need to be backwashing the filter at all? Pressure has not risen much at all, but not sure if it should be done regardless.

Pool is looking good, clear water but still lost about 9-10ppm of chlorine last night (from 34ppm to about 24.5ppm this morning). I took the levels back up to 35ppm this morning and will retest in an hour or so. I pulled the pool light fixture out last night as well, and did notice some small green areas around the ring of the light.

Is there a typical (I am guessing nothing is typical when it comes to pools) time frame it takes to eliminate the overnight chlorine loss?
Click to expand...

if backpressure hasn't gone up, then no need to backwash. just keep an eye on it.
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply