Questions about killing algae

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Thank you; as of this morning the PH is somewhere between 7.2 and 7.5, so I take it that it's a go to start SLAMing. My plan is to begin this evening around 6 pm, hopefully.

I note that the ABCs link says "A PH level of 7.7 and 7.8 is ideal, but really anything between 7.5 and 7.8 is doing fine, while levels between 7.2 and 8.0 are acceptable for swimming." But the SLAM page, just as you said, does say to adjust PH to between 7.2 and 7.5, which I have now done. That's lower than what ABCs says is ideal, which is interesting... I'm guessing that maybe the lower PH is more lethal to the algae perhaps?

When the SLAMing is over, do you recommend that I continue to raise the PH until I'm between 7.7 and 7.8?

Also, I figure I should brush the pool, but I read in the sticky at the top of the forum that I shouldn't brush until I see the green color start to fade. Honestly, the water doesn't really look green... it's the floor that looks green from the accumulation of algae on it. So, should I wait for the floor to look less green before I brush it?
 
Quote Originally Posted by Abigail K View Post

pH tends to rise by itself in a pool, it's not really necessary to deliberately raise the pH post-slam unless you're below the recommended levels.
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Zindar said:
Does this hold true with vinyl liners too? I know it's true with plaster pool, from my prior experience. But your advice is worth a try... I can monitor it over time and see if it starts moving on its own.
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Yes.

Remember, do not test pH when the FC is >10.

During the SLAM, you should be brushing at least daily and don't forget all the little nooks and crannies!
 
I started the slam about 1 hour and 15 minutes ago, and the results aren't what I expected. The chart said to shoot for a FC level of 24. I already had a level of 5, so I used the pool math to bring it up to 24. Slightly over an hour later, I did a chlorine test and got a FC level of 24 or 24.5 (hard to read tell exactly when all the pink disappeared.) I then added 5 drops of the other drops, which is supposed to make the solution pink if I have CC. It was just barely pink. It took 1 or 2 drops to totally clear it up again, so I guess I have a CC of .5 or 1. So

FC 24 - 24.5
CC .5 - 1.0

According to the rules does that mean I'm already in the follow up stage? I did just brush the pool, and maybe when the water settles a bit I'll run the vacuum to remove the algae. Also, I just removed the stair steps (was a struggle to do that), so I'll wash that down also. Other than that, does that mean I don't have to do anything until tomorrow morning to this pool?
 
What's weird about my water though: It's not green... but there is green algae - a fair amount of it - on the pool floor (or was before I started SLAMing... it's too dark out for me to tell now). And at 8:00 pm when I started this, I attempted to lift the stairs (but failed - I didn't get them out until 9 pm), and as I lifted them I could see green material in suspension in the water that was moving around the steps. The steps are hollow, so maybe there was algae inside the steps. When I did get the steps out, they look pretty clean - no green stains on them. But who know about the inside of them.

To me the steps are more trouble than their worth, and maybe I should have a simple deck ladder to descend into the pool. But I spent $280 for those steps, so I hate to stop using them. I envisioned that they would make it easy to get in and out, as one of my knees hurts a bit, and I also envisioned sitting on the steps, but in reality, I don't sit on them at all.

In addition, when I brushed the pool, I again felt bits of sand in the center of the pool. The algae is along the perimeter, but the sand is in the center. I'm guessing that since the water current from my jet moves counterclockwise around the pool, maybe it helps channel the sand to the middle. I'm starting to wonder if that sand is coming from the stair steps. I could see there are holes in various spots of the steps to allow water to act as ballast to hold the steps down, and there's also a fair amount of sand inside the steps to act as heavier ballast. But the water holes are higher then the sand level, so the sand is supposed to stay in there. Maybe the water turbulence induced by the pump allows sand to jostle around in there or something. But I'm just wildly guessing here.
 
Is the water clear?

Test again in the AM before the sun gets on the pool to see if you are still at 24.5. If it is 23.5 or less, keep up the SLAM

You may luck out with a very short SLAM
 
I think the water has always been fairly clear... a bit murky, but I could always see the bottom. But as for how it looks now, it's too dark to say, so I guess tomorrow morning I'll get up early and take a look at it. I hope that whatever treatment I give it tomorrow will be enough until the evening when I get back from work, as I need to go to work tomorrow.

I'm already getting bugged by my wife and son though, wanting to know how soon they can go swimming. Speaking of which, does anybody know the rules of thumb on when I can declare the pool safe to swim in? I assume I have to wait at least until the SLAMing is done, at which point the chlorine will still be high, but start to drift downwards. How low does it have to drift before people can swim?

Also, I think I read that the water needs to be clear to be done SLAMing, but is that really right? After the algae is all dead, doesn't the filter have to take possibly days to clear up the water? I'd think SLAMing would no longer be needed during this, and that it would be safe to swim.
 

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Okay, here we are 11 hours since I last put bleach in the pool, and the levels are virtually unchanged:

FC 24.5
CC 0.5

It's very lightly drizzling outside by the way, and light, but not very light (like morning twilight). But enough that I'm looking at the water, and the water is a cloudy green. Not a really thickly cloudy green, but it definitely looks cloudy green to me. Somehow I don't remember it looking that cloudy before. It doesn't seem possible to me my treatment would make it get cloudy, but maybe it could because:

1) I've been running the pump nonstop since I started SLAMing, and
2) I brushed the pool less then 10 hours ago, which probably jostled up all the algae.

I guess now that it's light, I'll go run the vacuum now to see how much help that might yield me.

Does it make since that my FC has held solid with my CCs being fairly negligible, and yet I still have green water?

I did wipe down my steps with a 1:1 mixture of tap water:8.25% bleach, and the steps are not in the pool yet... I wanted to make sure the pool is clean before I put them in.

Oh, I should mention one other thing... About a day or two before SLAMing, I cut back my inline chlorinator (with 3" pucks) to 50%, and about a half day to one day before, I cut it off entirely by turning the dial to zero. There are still pucks in it, but since the dial is at zero, I'm trusting that it's not putting any chlorine via the pucks in there.
 
Zindar said:
I think the water has always been fairly clear... a bit murky, but I could always see the bottom. But as for how it looks now, it's too dark to say, so I guess tomorrow morning I'll get up early and take a look at it. I hope that whatever treatment I give it tomorrow will be enough until the evening when I get back from work, as I need to go to work tomorrow.

I'm already getting bugged by my wife and son though, wanting to know how soon they can go swimming. Speaking of which, does anybody know the rules of thumb on when I can declare the pool safe to swim in? I assume I have to wait at least until the SLAMing is done, at which point the chlorine will still be high, but start to drift downwards. How low does it have to drift before people can swim?

Also, I think I read that the water needs to be clear to be done SLAMing, but is that really right? After the algae is all dead, doesn't the filter have to take possibly days to clear up the water? I'd think SLAMing would no longer be needed during this, and that it would be safe to swim.
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It is safe to swim with FC between min and SLAM shock FC level, based on your CYA; assuming the water is clear and you could see anyone on the bottom if they needed help.

Using the pool during the SLAM process will slow the process, but it will still get done. Folks using the pool should shower/rinse before and after the swims.

Yes the water needs to be clear before you pass the 3 criteria to determine a SLAM is done. See red lines in my sig. Stopping the SLAM too soon could put things back to square one :grrrr:

Rain has very little effect on the pool chemistry. Just keep testing and adjusting. :smile:
 
Fortunately the rain was very brief, and not a heavy rain. Meanwhile, I pass two of the 3 criteria for being done with the SLAM, but I fail the clarity test. The water is cloudy green, and it's hard to see the bottom. You can see bright objects on the bottom (like the white vacuum head), but the view is blurry.

So with this being failed, I'm instructed to continue SLAMing, but the SLAM instructions say to bring the FC back up to 24. It's already that high; it's not dropping. Well maybe now it is, being that it's daytime, but it's mostly cloudy today. I think bits of sun may be poking through though.

I'm at work right now, but when I get home I can do another chlorine test, and I guess it sounds like if the water is not clear, then I should bring the FC back up to 24, assuming that's it dropped any since then. I have not added any bleach beyond the intial SLAM, because the FC never dropped, even as of this morning.

Butterfly said:
It is safe to swim with FC between min and SLAM shock FC level, based on your CYA; assuming the water is clear and you could see anyone on the bottom if they needed help.
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Well as for people being on the bottom, everybody in my household (namely myself, my wife, and my 14 year old son) are expert swimmers, so I don't think this will be a problem

Butterfly said:
Using the pool during the SLAM process will slow the process, but it will still get done. Folks using the pool should shower/rinse before and after the swims..
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Oh... I guess then if they're desperate they could swim then, even though the FC is way up there at 24, and the water is cloudy green? I'll mention this, but they problably won't do it because I've not yet reinstalled the stair steps, so they've have trouble getting out of the pool. I can do it by doing a reverse triceps extension (with my back to the wall), but my wife isn't strong enough to do that, and my autistic son won't think to do it, and it's hard to teach him things that quickly. (By the way, once I was in there with my son and no steps, and I boosted him out with my arms, and then I triceps'd my way out myself. But my wife is far too heavy for me to boost her out, so she didn't go in.)

Do you think it's safe, during the SLAM to put my steps back in there, or should that wait until the SLAM is done?
 
I just got home and measured:

FC = 17
CC = 0 - 0.5 (It was pretty much clear at 0, but I wasn't completely sure, but one drop, and it was crystal clear)

But the water is still green. So I've been SLAMing for almost 24 hours, the CC's have never significantly reappeared this whole time. But how can that be? If the water is green, doesn't that mean there's organic material that should be breaking down and forming CC's? I don't understand what's going on here.

Meanwhile, I guess I go now and add some bleach to boost it back up to 24.
 
duraleigh said:
Yes, sir. It is a process...never a one-time event.

Follow the SLAM process to a "T" and it will work.
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Okay, but maybe I'm misunderstanding how the SLAM works. While it's killing the algae, shouldn't the CC's be moving up?

- - - Updated - - -

Put another way, here's a quote from the SLAM sticky at the top of this forum:

"To see if you got all of the algae, measure the FC level after sunset and then measure it again very early in the morning. If the FC remained stable (within 0.5 of the same reading) overnight, and the CC level is 0.5 or lower then all of the algae is gone. If you don't have a good test kit, you should maintain shock level until the water is completely clear and sparkling."

According to this test, my algae is gone, but yet my water is still green, albeit not a dark green. How can this be?

- - - Updated - - -

Wait, I discovered something that might be relevant, or maybe it's not; somehow my water jet (my above ground pool only has one jet) was pointed almost straight down. I just moved it to point sideways to give better water circulation. Maybe this was interfering with the skimmer's ability to route the algae to the filter.
 
Today's a little different... I haven't treated since arount 7:00 pm yesterday, whcih was 12.5 hours ago, and I'm slightly later this morning checking than yesterday morning, and now I get

FC 22.5
CC 1.5

I had tried to add the right amount of bleach yesterday to achieve 24.0.... hopefully I measured it right. If so, overnight it lost around 1.5 of that, and gained 1.5 CC in it's place.

So I assume right now I should add just a small amount of bleach to boost it back to 24.0

Does it make sense that FC could be as high as it is (i.e. almost at shock level), and CC could be as high as it is, despite that? I'm only going to add a small amount of bleach, enough to raise FC by 1.5, so I'm not sure that action will do much to get rid of my 1.5 CC.

The water is still cloudy, but I'm not so sure that the color is greenish... it kind of looks bluish, but I should mention my vinyl liner is blue, so it's hard to tell what color the water is. Maybe it's bluish gray with a little greenish.
 
Update on my status: Here is the graph of measurments:

Code: 
Date	Time	FC	CC	Notes
------	-------	----	-----	---------------------------
7-23	8:05pm	24-24.5	.5-1.0
7-24	6:30am	24.5	.5	I brushed and vacuumed here
7-24	6:30pm	17	0-0.5	At this point, I moved the jet
				to point sideways instead of down
7-25	7:30am	22.5	1.5	Water now bluish cloudy instead of greenish cloudy
7-25	9:20pm	14	1.5	I brushed again at this point
7-26	7:45am	24.5-25	0.5	Water is now clear!

Interesting note on the above: Once I moved the jet, the CC's started jumping, and my green started disappearing. I don't know if that's coincidence or not.

So I think I'm passing all three tests now. Does this mean the SLAM is over, and I can now do the following:
1. stop running the pump 24/7
2. Put the steps back in the pool
3. Let the chlorine drift down now.

Actually the chlorine is now still at shock level, so I'd not add chlorine at this point even if I wanted to.

I also owe many thanks to the superior methods I've learned on this forum. At first I wasn't sure if I wanted to go to the trouble, but I think what pushed me over the edge is when I found out my chlorine pucks were adding CYA (which pool store employee has ever told me in my many years of business with them).

On another note, now that the water is clear, I can see a small bit of what looks like sand in the middle. The steps are out of the pool though, so I pretty much rule that out as the source, and the only other source I can point to is the sand filter.

Edit: No, I can't rule out the steps. The water has been so cloudy that the sand could have been in there a long time. But I could swear that I vacuumed like within two minutes *after* I removed the steps, so I have my suspicions. Maybe I should vacuum right now, and leave the steps out, to see if the sand returns.
 
Update: I don't think that was sand. I tried scooping some with a spoon, but it wasn't granular, and it immediately dispersed if I got anywhere close to it with a spoon. It's basically tannish in color, like sand, but I suppose there could be a faint greenish hint to the tan. Given the texture, I'm wondering if it was dead algae. So I just vacuumed the pool thoroughly, and to be safe, I guess I should leave the pump running. It's still at shock level from my last night's treatment, so maybe through the course of today, if it's not already completely sanitary, hopefully it will be by later today.
 

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