What am I doing wrong?

[DJSO]

So, I'm fairly new to all of this. I did go through the SLAM process about a month ago and turned my green pool back to clear. Then we went out of town for 4 days. I set the auto chlorinator to feed Trichlor tablets while we were gone. The pool seemed fine when we returned, but just not as clear as I know it can be. So, I vacuumed, cleaned filters and Started another SLAM process...

Now, the Water looks great, but I can't pass an OCLT.

Chemistry readings are:
CYO -40
CC -.5
FC- 11
PH -7.6
TA-100

I am adding 12.5% liquid shock and have my chlorinator turned off. I am bringing FC up to 16, but it keeps dropping to 11. What am I missing?

 

[jblizzle]

When are you adding the final nights chlorine? When are you testing it at night? When are you testing it in the morning?

 

[Abigail K]

Looking through your post history, I would suggest removing pool lights (if you have any - this isn't clear from your posts) and scrubbing the light niche.

 

[pwrstrk]

Do you have any lights in the pool ? Check the light niche. Sometimes algae likes to hide out there. ?

 

[pwrstrk]

Whoops. Must have posted when Abby did. ?

 

[Divin Dave]

I suggest you do an OCLT (Overnight Chlorine Loss Test).
test your water just when it gets dark.
test again before the sun comes up.

If the FC loss is more than about 1 ppm, then there is something organic in the pool consuming your FC. If so, it will require a Slam again.

Be sure to clean out behind any lights. Algae love to hide behid them.

If you havent ran your waterfall in a while, algae like to hide in those pipes too. That needs to be checked.
any other water pipes that dont get constant water circulation through them. Check those and run them to get anythign that might be in there out.

If you pass the OCLT, then you might need to bump up your CYA just a tad. (40 should be fine though 95% of the time) Pools in Full Sun all day long will suffer more FC loss due to UV than pools that are in the shade.

Do the OCLT first though to see if there is algae hiding somewhere.
if you have a auto fill, put some chlorine in that too. Algae like those as well.

hope this helps,

 

[DJSO]

Starting overnight test by Testing around 9 PM, adding shock per pool math. Re-testing around 10:30pm. Then testing again at 8AM. I've then had my husband add shock during the day to bring back up to shock level based on the 8AM test, but he can't recheck during the day to ensure it got high enough, we are just trusting the pool math until I can test again at night.

 

[DJSO]

Thanks for all the responses. I have not run the waterfalls since being home because I didn't want to involve that system until the pool was settled. However, I'll turn them on to see if that is the source. I checked around the light, but didn't fully pull it out. First, because I didn't think of it....Second, because I don't know how! Any suggestions? I know it is a Jandy LED. Should it unscrew like a light bulb? Or does it just pull out? Sorry, I should probably know how to do this!

Also, I have an auto cover. It's been cold and overcast here and since no one wants to swim, the pool has been kept covered. I leave it open for about an hour after I shock it, then close it up again. Could this be having an effect?

 

[pwrstrk]

There's something organic in the water consuming chlorine. That's a long time to go without testing and bringing your FC back up to SLAM level.
The whole key to the SLAM process is maintaining the shock level. It makes the process move along quicker.
Does the cover have any visible algae on it ? Otherwise I would think the cover would help because it would take the sun out of the equation somewhat from burning off the chlorine. ?

 

[Kiss4aFrog]

Looking through your post history, I would suggest removing pool lights (if you have any - this isn't clear from your posts) and scrubbing the light niche.

That and if you have a removable ladder, pull it and check the bottom (underside) of the steps. Making sure the waterfall gets some of the SLAM water is also a good call along with checking inside the skimmers and the back of the skimmer doors and inside the waterfall fitting to make sure something isn't growing in those areas too.

You could be losing that much FC due to the time involved in putting it in and then waiting so long before dosing again. If the FC isn't at SLAM level it isn't killing algae. It might be keeping it from going full blooming green but you have to maintain that FC level for as long as it takes to kill your algae. Each time your FC drops below the SLAM level you are just wasting bleach and your effort.

 

[Abigail K]

Jandy LED lights have a (Philips) screw on the faceplate, typically at the 12 o'clock position. Unscrew it and the light hinges away, push up from the 6 o'clock position and it should come off.