Opened my pool last weekend and will have questions...

[TN94z]

So I just opened my pool last weekend and I figure there will be questions that come up pertaining to this, so I wanted to create a post for all of my opening questions so it will be easier for me to find in the future.

So far I have only had the filter running and I added some water but have done no tests yet (I've been too busy at work).


The water looks pretty good with the exception of some trash in the bottom. But as I pulled the lid off of my skimmer, I noticed that the white portion of the skimmer was green. Part of the skimmer lid is exposed to the weather as the cover only makes across half of the skimmer lid. I didn't notice any green anywhere else in the pool...just the skimmers. I know I need to get my tests done first, but is this something to worry about?

Another issue I have is my concrete obviously settled and my brick coping around my steps had become loose. So loose I could pick up a chunk of about 8 bricks (I'll never go with brick coping again by the way).

 

[frustratedpoolmom]

Well algae starts to grow after water temps reach 60 degrees - so the water in the skimmer probably warmer. Once you get some chlorine in there your going to need to brush the skimmer surfaces thoroughly... Once all the debris is out of the pool, verify if your chlorine is holding and if it's not, you'll have to SLAM.

Without test results I wouldn't offer an opinion on what to do first. Good luck, keep us posted!

 

[TN94z]

Well algae starts to grow after water temps reach 60 degrees - so the water in the skimmer probably warmer. Once you get some chlorine in there your going to need to brush the skimmer surfaces thoroughly... Once all the debris is out of the pool, verify if your chlorine is holding and if it's not, you'll have to SLAM.

Without test results I wouldn't offer an opinion on what to do first. Good luck, keep us posted!

That's my plan. So it sounds like my thinking was on the right track. I am going to test the water today and see where I am with everything. I'll update! Thanks

 

[TN94z]

So here are my test results from this afternoon:

From the blue kit:
Chl=.5
pH=7.2

From the big kit:
FC=1
CC=0
TC=1
TA=60
CH=90
CYA=Filled the tube to the top...could still barely see the dot but it was getting close
Salt=1440

 

[Richard320]

So here are my test results from this afternoon:

From the blue kit:
Chl=.5
pH=7.2

From the big kit:
FC=1
CC=0
TC=1
TA=60
CH=90
CYA=Filled the tube to the top...could still barely see the dot but it was getting close
Salt=1440

Sounds pretty easy to fix. Even though you need FC and CYA, your pH and TA are already low, so I'd advise avoiding trichlor or dichlor powders or pucks. They lower pH. Stick with bleach. Scrub off that skimmer green. It goes contrary to conventional wisdom here, but in your case, adding the liquid bleach to the skimmer when you're done scrubbing might be a good idea!

CYA needs to come up a bit. I'd target 20.You already have some residual, so you don't want to overshoot. It's easy to add more later if it's still low.

PH will probably rise over time. Ta... wait a week and see. The water's still to cold to get in anyway, and you don't need to worry about dissolvoing plaster with your vinyl liner.

Once you're sure the algae is gone for good, add the salt and let 'er rip!

 

[TN94z]

Sounds pretty easy to fix. Even though you need FC and CYA, your pH and TA are already low, so I'd advise avoiding trichlor or dichlor powders or pucks. They lower pH. Stick with bleach. Scrub off that skimmer green. It goes contrary to conventional wisdom here, but in your case, adding the liquid bleach to the skimmer when you're done scrubbing might be a good idea!

CYA needs to come up a bit. I'd target 20.You already have some residual, so you don't want to overshoot. It's easy to add more later if it's still low.

PH will probably rise over time. Ta... wait a week and see. The water's still to cold to get in anyway, and you don't need to worry about dissolvoing plaster with your vinyl liner.

Once you're sure the algae is gone for good, add the salt and let 'er rip!

Okay, so now I have some questions:

1) You say to target CYA of 20. Reading in the pool school, it says a SWG should target around 70 which would put me at a FC level of 5. I understand the residual part and not wanting to go too high, but is 70 what I'm trying to achieve?

2) Do I need to wait until the CYA is at target before getting my FC to target? (I will be using bleach)

3) After I get these correct, I add the needed salt (assuming the algae is gone)

 

[Richard320]

Okay, so now I have some questions:

1) You say to target CYA of 20. Reading in the pool school, it says a SWG should target around 70 which would put me at a FC level of 5. I understand the residual part and not wanting to go too high, but is 70 what I'm trying to achieve?

You say "Filled the tube to the top...could still barely see the dot but it was getting close." So you probably have some CYA in the water. If you count it as zero, when you add more, you'll end up too high. By targeting 20, you'll likely end up somewhere between 30 and 40. And if not, it's easy enough to add more. You'll be addimg more later anyway. 70 is the target after the SLAM. Do you want to maintain 12 FC during the SLAM, or 28? That's a whole lot of bleach, but that's the difference between SLAMming at 30 CYA versus 70 CYA.

2) Do I need to wait until the CYA is at target before getting my FC to target? (I will be using bleach)

No. Assume whatever value you targeted is there and dose accordingly. If the pool is green and yucky, the FC won't stay too high for more than a few minutes. And CYA starts working before it shows up on the test.

3) After I get these correct, I add the needed salt (assuming the algae is gone)

Yes. After you pass all three tests to indicate the SLAM is done, you can raise CYA to your normal target and add the salt. No point adding salt if you'll just be backflushing it out when the filter loads up.

 

[TN94z]

I got you. I was thinking I didn't need to SLAM. The water looks good. The walls look good. There is some debris that needs to be vacuumed out, but no sign of algae other than inside the skimmer boxes. So I guess I need to get the chlorine up and keep the CYA on the lower side "in case" the chlorine doesn't hold and I need to SLAM?

That's where my confusion was coming in. If I may have to slam, then yeah, I don't want to get my CYA up high.

 

[duraleigh]

If your water is clear, there is no reason to SLAM.

That said, you report green (algae) inside the skimmers so that means I would SLAM the pool just to be safe and get started with no algae at all. It will likely be a quick SLAM but I would agree with Richard320 that it is the right thing to do. Get the debris all out first then SLAM away.

 

[TN94z]

If your water is clear, there is no reason to SLAM.

That said, you report green (algae) inside the skimmers so that means I would SLAM the pool just to be safe and get started with no algae at all. It will likely be a quick SLAM but I would agree with Richard320 that it is the right thing to do. Get the debris all out first then SLAM away.

Sounds good! I'll get started on that

 

[TN94z]

I started my SLAM process today. The water has been clear since opening. I vacuumed today and brushed the walls before starting the SLAM. I added some of the bleach via the skimmer as I scrubbed the green off the skimmer boxes.

I have been testing on the hour. I added enough CYA for a target of 20-30. I added enough bleach to reach a target of 12 FC. After allowing everything to run for an hour, I did a test and got a reading of 8 for FC and 0.5 CC. So I added enough bleach to go from 8-12 FC. I tested an hour later and got a reading of 13.5FC and 0.5 CC. I waited another hour and tested and got 12-12.5 FC and 0.5CC.

I will test again in another hour but I have a question. If I run another test in an hour and my FC has dropped again, but the CC is still at 0.5, does this tell me that I have something growing or what? Or is this just because my SWG is not running to keep the FC up? I thought, from my reading, that if you had something the FC was fighting, the CC would go up because it is a byproduct of that? Am I misunderstanding this?

 

[Richard320]

Probably. .5 CC is the cut point. If you're happy with the way the water looks, and the CC is only.5, then you could do the overnight chlorine loss test tonight. Be sure you don't have the SWG running for that. If it passes, you're done with the SLAM. If it doesn't pass, it's a good thing you started now!

 

[TN94z]

Probably. .5 CC is the cut point. If you're happy with the way the water looks, and the CC is only.5, then you could do the overnight chlorine loss test tonight. Be sure you don't have the SWG running for that. If it passes, you're done with the SLAM. If it doesn't pass, it's a good thing you started now!

I guess my question is that the FC has been lower every time I check it. Should that "hypothetically" stop dropping at night?

 

[Richard320]

I guess my question is that the FC has been lower every time I check it. Should that "hypothetically" stop dropping at night?

Yes. You lose FC to two things: organics in the water and UV degradation. Testing it at night eliminates the possible UV losses. If it stays up, it's not being used killing anything. OCLT instructions

 

[TN94z]

Yes. You lose FC to two things: organics in the water and UV degradation. Testing it at night eliminates the possible UV losses. If it stays up, it's not being used killing anything. OCLT instructions

I remember that now... Sounds good. We will find out in the morning. Thanks!

 

[TN94z]

Okay, I did a test last night after dark and the FC had fell to 10.5FC. This morning I tested and it had fell to 7.5FC. There wasn't direct sunlight but the sun was up. It was just behind some trees. The CC has stayed steady the entire time. On the CC test, it just barely turns a light shade of pink (nowhere near what it is to begin with) and one drop of R871 turns it clear easily. That's how it's been the whole time.

I know that I need to continue the SLAM since the FC dropped overnight, but shouldn't the CC be going up as well? I guess that's where I am misunderstanding the results.

 

[pwrstrk]

You can still have low CC's and still fail the OCLT. Maintain SLAM level until you can pass the OCLT. ?

 

[Richard320]

That sounds right, actually.

Chlorine oxidizes organic stuff - sort of flameless combustion. So imagine a fire. Combined Chlorine is the equivalent of smoke - imperfectly burned stuff. Although sometimes you get a really hot fire going and there is no smoke, ie no CC.

So...
Chlorine + organics (skin cells, leaves, algae, etc) = Combined Chlorine.
If you have no chlorine, you will have no CC, because you're missing half the equation.
If you have no organics, you will have no CC, because you're missing half the equation.
Since FC is being used up oxidizing something, you'd expect it to drop and CC to go up.

That's why we say you're done when you have hardly any CC and hardly lose any FC. You've eliminated the organics. There's nothing left to oxidize. There's no more fire. It's burned itself out.

 

[TN94z]

Here's a few pictures of my pool water. The water has pretty much looked like this since day 1.

View attachment 29457
View attachment 29458

 

[Richard320]

Is there any chance you have a ladder or steps in there that could be hiding some algae? How about a light? We've had people chasing the FC loss for days and found it behind the light or inside the ladder pipes or beneath the steps.