Why is my pool so cloudy? All chemistry levels in check

[SW Pool Owner]

Sorry should have specified, I've been SLAMing since about Sunday

Pool is clearing up but will raise back to shock level again today, just bought 12 bottles of liquid shock, just waiting for the sun to go down

 

[IceShadow]

If you're SLAMming you need to be raising your FC back to SLAM level multiple times a day. The more you can keep it up there the quicker the process will go. And if you're not crystal clear, the SLAM isn't done and you should be continuing with it.

 

[mknauss]

Pool is clearing up but will raise back to shock level again today, just bought 12 bottles of liquid shock, just waiting for the sun to go down

There is NO reason to wait for the sun to go down to add chlorine to maintain your SLAM level FC. Do it as often as possible.

 

[SW Pool Owner]

Ah ok, just added 4 gallons of 12% sodium hypochlorite. FC went down to 17.5 in 8 hours, which is progress from the 10 ppm I chewed through yesterday. Hoping this is the last batch of Chlorine I need to add, but I have 8 more bottles ready..

- Brushed and saw some green still floating up, saw some visible algae on skimmers so brushed that
- Ran my waterfall for good measure in case there's anything in there, even though this causes quite some water loss for me

How does CH relate to my heater, and should I be worried?

Thanks

 

[mknauss]

Low pH is a concern for a heater. Not SLAM level FC.

 

[Mdragger88]

No worries-
I was referring to calcium hardness since u were regularly using cal hypo which increases calcium hardness with each dose.
Generally vinyl lined pools don’t need to be concerned with low ch unless they also have a gas heat exchanger- in which case 200ppm ch is sufficient.
All pools & swg’s risk scaling with high ch level thus the recommendation to cease use of cal hypo when you reach a ch of 200ppm or so. This can be adjusted after slam is complete.
As @mknauss mentioned low ph is also a concern for heaters. Yours is fine.
Keep with SLAM Process until u meet all the exit criteria.

 

[SW Pool Owner]

I have a gas heater and low CH. Should I be scared?

 

[mknauss]

I have a gas heater and low CH. Should I be scared?

Most gas heater manufacturers recommend CH level of 200 ppm give or take. That is from the days of steam boilers. A pool heater is no steam boiler. But CH over 150 ppm is a good idea. If possible.

 

[SW Pool Owner]

Just an update, I think we're done with SLAM, however a little confused by readings but willing to assume it's margin of error.

Last night FC was at 28
it rained last night
this morning I measure at 30
pool smells like chlorine gases around some parts

So OCLT, the chlorine went.. up? I will just assume I overcounted or missed a drop or two somewhere. Pool is clear, will let the sun do the work to bring chlorine down now.

I just wonder how it got to this point because I measure my FC almost daily and I never went below 6 ppm, always tried to keep it higher around 10ppm.

I'm not sure but I hope I don't have to do this again, I think I went through over $250 of chlorine shock and 5 days of brushing / measuring / adding chlorine... It's great that I WFH otherwise this would've been impossible !

 

[Texas Splash]

Sounds like there was some testing issues, but I agree you seem to have met all the SLAM requirements. Unless there was an obvious patch of algae growing somewhere that was undetected, it's difficult to know how/why you had found yourself in this SLAM scenario. We can only do our best to manage the levels properly, manage unusual weather events, and be proactive if something seems odd. Just imagine what your water would look like if you didn't take action quickly? With about 45 days or so remaining in your season, it's good you are clear now. Hopefully it stays that way until closing.

 

[SW Pool Owner]

Yes, in hindsight when I noticed the water turn a little cloudy I should have started SLAMing right away instead of assuming it was pH or something else because my FC were high enough.

I think maybe the waterfall may have something to do with it, since it's off most of the time and then I finally ran it a few days before it turned cloudy. Perplexing, but my gf has a pool party this weekend so I'm glad I was able to resolve

Thank you all

 

[jeffchap]

I turn my waterfall and fountain on periodically just to flush out any stagnant water in the plumbing that may be harboring algae.

 

[SW Pool Owner]

Just an update, I measured the FC 5-6 hours later and it seemed to have dropped 3-4ppm in direct sunlight.

It made me a bit nervous, especially as I just turned on the waterfall so I dumped 2 more gallons of 12% shock in there, which should raise FC to about 29

 

[Texas Splash]

Just an update, I measured the FC 5-6 hours later and it seemed to have dropped 3-4ppm in direct sunlight.

It made me a bit nervous, especially as I just turned on the waterfall so I dumped 2 more gallons of 12% shock in there, which should raise FC to about 29

That's a large drop. It should only drop that much in 24 hrs. Good you bumped it up, but still odd as to why that is happening?

 

[Mdragger88]

It doesn’t hurt to keep slam level for one more day & confirm your Overnight Chlorine Loss Test again. It’s good insurance.

 

[Texas Splash]

After second though, I should clarify as I think more about your scenario. If you were at SLAM level this morning, let's say 24 or so for example, the FC WILL fall quicker as it tries to go down to the normal FC-to-CYA range noted on the FC/CYA Levels. Since you just passed all 3 criteria, that could very-well be why the excess FC drop this afternoon. You might just let it fall in the next day or two down to the normal range THEN see if it holds better. It should.

 

[SW Pool Owner]

That's a large drop. It should only drop that much in 24 hrs. Good you bumped it up, but still odd as to why that is happening?

Not sure but im ready for war, Ive got 6 more bottles of shock and a 12 pack of powdered calcium shock ready to go. I suspect its the waterfall, it has to be ..

 

[SW Pool Owner]

After second though, I should clarify as I think more about your scenario. If you were at SLAM level this morning, let's say 24 or so for example, the FC WILL fall quicker as it tries to go down to the normal FC-to-CYA range noted on the FC/CYA Levels. Since you just passed all 3 criteria, that could very-well be why the excess FC drop this afternoon. You might just let it fall in the next day or two down to the normal range THEN see if it holds better. It should.

Ahh ok. Yes my pool gets direct sunlight for hours from 8AM. It's been hot in NY and I start dripping 30 seconds out there..

The dropoff in that case of trying to return to stable levels makes sense, but I'm going to let it sit at SLAM levels one more day. I'm exhausted and I want to see this finished all the way through. I won't add any more chlorine from now on, let's see what tonight's OCLT looks like

 

[IceShadow]

Two notes:

1) Yes, FC will have a higher dropoff the higher of a concentration it has, so a higher dropoff when your FC is up at SLAM levels due to sunlight is expected.
2) It's a really good idea to keep up at SLAM levels for an extra day or two when you think you're done to be safe, so that's a good thing to do anyway