Went away for two days and the pool went green. I think I know what went wrong, I hope..

[Skenn81]

Not much of an update but for all the people watching the thread..

I got the toilet brush and went in the pool last night and scrubbed the light niche. SO MUCH DUST AND DEBRIS! That thing must have been in there for years because the amount of stuff that came out was very impressive. Nice and smooth in there now so that's taken care of. I am putting the light back in after work today. Overnight CL again was before the sun went down. Same as yesterday over about the same amount of time, down to around the 21 mark after I added the CL after dinner. Jacked it back up one more time this morning.

Looks like we are just about done here.

 

[Skenn81]

Ran one more overnight test, am I done or do I need to keep these levels up? The CL went from 22.5/23 to 20 this morning. CC test came back fine, pool is as clear as it could possibly be.

 

[JoeSelf]

You lost more than 1 FC over night. SLAM not complete. SLAM Process

Got this right from the page.

You are done when:

• CC is 0.5 or lower;
• You pass an Overnight Chlorine Loss Test
  This test is intended to determine if your pool has a contaminant such as algae that is consuming chlorine. The test is performed by testing FC in the evening after sunset and again in the morning before sunrise. The readings will be the same if there is nothing in your water consuming chlorine.
  " style="box-sizing: border-box; background-color: transparent; color: rgb(0, 0, 0) !important; text-decoration: none !important; border-bottom: 1px dotted rgb(0, 0, 0) !important;">OCLT (ie overnight FC loss test shows a loss of 1.0 ppm or less);
• And the water is clear.

When all three are true, you are done SLAMing and can allow the FC to drift down to normal levels.

 

[Skenn81]

Well then it's back to the store this afternoon for another 3 jugs and the process will continue. Where else can I have the problem? Could it be in the filter? Do I need to clean anything else? The light niche was scrubbed, I have no ladders, nothing else is around...

Except folks used the pool though, like I was in there swimming to get the light reattached and people put their legs in at night. Could that be doing it?

24ppm here we go.. again.

 

[kimmielea]

What time are you doing your final testing at night? In post #41 you commented that "Overnight CL again was before the sun went down." To get an accurate OCLT, you need to do the test after dark and then again before the sun comes up.

 

[Skenn81]

Test which read 46 drops was after sun went down in the dark. Morning test I could not get up before 6am so was done closer to seven. Sunrise here is about 630.

Does the heat matter or just the sun as it's melt your face out almost 100 all day long and it really doesnt cool down much after dark.

I know I just need to get up at 6 to test this but I don't want to move! Should I take the pool light back out or be spraying down the filter cartridge to clean things? Pool light was out for a while and niche scrubbed down, just screwed it back in last night.

 

[kimmielea]

The sun burns off chlorine quicker. I use less chlorine when my pool has the solar cover on or on cloudy days.
You should be ok to test at 7, as long as the sun is not hitting your pool yet (I have a tree that blocks the sun until around 9:30ish).
I can't answer about the light as I don't have one, but from seeing other posts, usually they'll leave it out until the OCLT is passed.
As far as the filter, again, I have sand, but I've seen in other posts they usually have a back up filter. A clean one and the other in the filter. Again, you don't change swap/clean until PSI is 25% above your clean PSI. You can also use a TSP solution to clean the filters (not sure of the ratio of TSP to water).

 

[Skenn81]

Well I think we're done. Either my readings last night were a little off or I lost count, but this morning the drops to turn it clear were the same as the drops last night.

So even though this was a SLAM, can I run an over night test any time to check if everything is okay? Like once I get the levels back down near 10, on a normal night after dark and before dawn it shouldn't drop in a similar fashion?

Also, what do I do now about the pH to get it back to a normal level?

 

[kimmielea]

PH won't read accurate until your chlorine is under 10.
Post a full set of test results and we'll help you get your levels adjusted.

 

[ajw22]

You can run an Overnight Chlorine Loss Test anytime you want to check your water.

 

[mknauss]

can I run an over night test any time to check if everything is okay?

Absolutely. That is a great test to do any time you suspect algae in your pool water.

 

[Skenn81]

And what may be the final update for this thread, CL dropped below 10 finally. Ran a pH test and it was right at 7.6, so no real issues there as it will rise with the Florida rain. Pool is looking a clear as can be and we are all happy campers. Thanks again.

And of course, picture for reference. Can't get any better than this.