Pool SLAM advice needed

[aeh0603]

Does that mean my water should lose the green hue once the algae is dead? Does dead algae turn brown? With all the chlorine I dumped in the pool prior to draining it, it never lost its green color, which has me wondering if that means it never died, or if it's possible for it to still be green even after it's dead.

Yes, once the algae is dead it is no longer green, it's more of a white or very light tan color. Your water should progress to a lighter green, to blue and cloudy, to blue and clear-ish, to crystal clear with no visible signs of algae. When you get to the blue and cloudy stage, that means your algae is primarily dead and it's up to the filter to remove it from your pool. Continue to test FC and increase your chlorine to SLAM level at least 2-3 times per day until all three SLAM criteria are met:
1) Water is crystal clear with no signs of algae
2) CC is 0.5 or less
3) You pass the OCLT (overnight chlorine loss test) meaning you lose no more than 1 FC overnight

As a side note, I'm not sure if this has been mentioned on your thread or not, but it's safe to swim if FC is at or below SLAM level (and above minimum) for your CYA, and you can see the entire bottom of the pool

 

[jessman1128]

Yes, once the algae is dead it is no longer green, it's more of a white or very light tan color. Your water should progress to a lighter green, to blue and cloudy, to blue and clear-ish, to crystal clear with no visible signs of algae. When you get to the blue and cloudy stage, that means your algae is primarily dead and it's up to the filter to remove it from your pool. Continue to test FC and increase your chlorine to SLAM level at least 2-3 times per day until all three SLAM criteria are met:
1) Water is crystal clear with no signs of algae
2) CC is 0.5 or less
3) You pass the OCLT (overnight chlorine loss test) meaning you lose no more than 1 FC overnight

As a side note, I'm not sure if this has been mentioned on your thread or not, but it's safe to swim if FC is at or below SLAM level (and above minimum) for your CYA, and you can see the entire bottom of the pool

Ok, thank you. Presumably the algae gets killed off in stages - for sake of discussion, let's say the first addition of chlorine to SLAM level kills off 10% of the algae that is present, the second addition kills off the next 10%, and so on? And if I wait too long to raise it back to SLAM level some of the living algae will likely be reproducing, thus increasing the algae quantity higher than what it might have been otherwise? If it's not possible for me to test and add chlorine more than twice a day on some days, would it be better for me to add it to higher than SLAM level in the morning to try to keep it from falling below SLAM level before I get home in the evening and can add more? I'm just trying to figure out why I never really saw any visible change in the water with all the previous days I was SLAMming - I guess the presence of all the tree material was one factor - maybe the main factor that resulted in no visible change in the water?

 

[mknauss]

Do not go above SLAM level FC. As long as your FC is above the minimum FC as shown in FC/CYA Levels you are killing algae, albeit slower than if the FC is at SLAM level.

Algae can create biofilm to protect it from contaminants. So brushing, vacuuming, etc breaks that biofilm.

Try to to test and add at least three times per day, morning, after work, before bed.

Lots of large organic material really slows down a SLAM. And exacerbates the amount of dead material that must be filtered out.

 

[jessman1128]

CYA was low last night after filling the pool the last few inches. 10 at best. pH was at 7.5 so I added acid to drop it to a planned 7.2. Added chlorine to bring it up to 10. Must have overestimated though because it was above 10 when I checked later before bedtime, and again this morning. Not quite sure what to make of that. Posting from my phone so too hard to list all the numbers but they're in my sig link. I brushed the walls and a tiny section of the floor this morning before work. The whale brush is so great! First time ever using it. I didn't brush more of the floor because I didn't want to overwhelm the filter during the day while I'm at work. Just the walls and one small section of floor stirred up a bunch of stuff. Looking forward to seeing how it's doing when I get home tonight. Oh and CYA appeared to be a bit over 20 this morning so I added bleach for 30.

 

[jessman1128]

The battle continues! Friday night when I got home from work the water was a bit murky, definitely still green, but the bottom was fairly visible. FC had dropped to 8.0 during the day. I added 25oz of 12.5% bleach to bring it up to 12 and by morning it had dropped to 10.5. I had to be gone all day Saturday, which is very unusual for me. I added 10 oz of 12.5% bleach to bring it to an intended 12 before leaving Sat morning, and 12 hours later when I was home and able to measure it again it had only dropped to 11.5 FC. This afternoon it was still green, but the murkiness had dissipated enough that I could make out the bottom fairly well, so I decided to take advantage of that and vacuum. I vacuumed about 1/4 of the bottom, cleaning the filter a couple times during the process, and then the water returned to the murky status and I could no longer see the bottom and didn't have any more time. This evening when I had more time the FC was at 12.5, CC 0.5. 12.5 is a tad over SLAM level with CYA of 30 so I didn't add anything and decided to brush the walls and vacuum the rest of the pool floor blind as it were, not being able to see it, but being able to feel along the bottom pretty well. Fairly certain I covered at least 75% of the bottom likely closer to 90%. I had to clean the filter a couple more times during this, and when I checked my levels again 90 minutes from the previous check of FC 12.5, CC 0.5, FC had dropped 2 whole points to 10.5, CC still 0.5. Wasn't expecting a drop of 2 FC in just 90 minutes, but I assume that's because I stirred up a bunch more junk with all the vacuuming. It's curious to me that my CC has not risen above 0.5 since the drain and refill. Prior to that it was regularly up to 1 and 1.5. Not sure what to make of that. A bit frustrated that I can no longer see the bottom, but hoping by morning time it will have started to re-appear with the pump running all night. Also, not too long ago my filter was getting clogged up pretty regularly, every 60-90 minutes. It's no longer doing that, it's lasting a number of hours at a time without getting clogged up. Not quite sure what to make of that either given that the water is still very green. I guess it's just that the particles of junk are much tinier now so they don't cause clogs nearly as quickly. I think I'm on the right track with all of this but it sure is taking a lot of patience and work!!

 

[aeh0603]

It's curious to me that my CC has not risen above 0.5 since the drain and refill. Prior to that it was regularly up to 1 and 1.5. Not sure what to make of that.

This is a good thing and shows that by draining you were able to remove a significant amount of the algea. CCs burn off in the sun 0.5 or less is where you want it to be ?. More than that is indicative of a problem.

Also, not too long ago my filter was getting clogged up pretty regularly, every 60-90 minutes. It's no longer doing that, it's lasting a number of hours at a time without getting clogged up. Not quite sure what to make of that either given that the water is still very green.

More great news! This is another sign of the progress you have been making in your SLAM, you are getting ahead of the algea at this point and are killing it faster than it's reproducing. It's no so much an indicator of the size of the particles being trapped as it is an indication that the number of particles in your water is decreasing.

These are both really good things and are proof that all the hard work you are putting in while following the SLAM procedure is working! Keep it up and your will be sparkling in no time!

 

[jessman1128]

I need to start taking pictures of the water each time I test the levels or do maintenance. I quickly forget the specifics of how it looked once a day or so is past. I think the water appearance didn't change much overnight Sunday. Monday morning I had FC 10.5, CC 0.5. Added ~10 oz of 12.5% bleach and went to work. 10 hours later (sunny day) FC had dropped all the way to 6.5 and the water appearance quality had degraded noticeably. Very green and very murky. Bottom definitely not visible. I got FC back up to 12 and brushed the walls. Water appearance has stayed the same since then. Visibility is about 18-24 inches down, then too murky to see anything. I have a few thoughts/theories, and a number of questions, after reading through a number of other threads on this site over the past couple of days, as well as watching a video my wife just sent me a short time ago.

My filter not getting clogged up as quickly is good news, but it is taking forever to get all the algae out. I'm wondering if now that the particles are smaller if it's getting clogged up without being clogged up. Let me explain...the water throughput is not clogged up, but the filter's ability to trap any more particles of anything is severely impeded...so water is pushed through efficiently, but no more particles get captured and they pass on through with the water. When I take the filter out now to clean it it's not as filthy visually - in other words, there are more areas that appear to be white or white-ish at first glance than previously - but perhaps there are tiny particles that are stuck to those sections that don't really show up color-wise but still prevent that part of the filter from capturing any more particles. Is that possible?

In one thread that I read, the pool owner lamented that he/she was getting so frustrated at watching all the little bits of green algae shooting out through the return jet when vacuuming. They "solved" that by upgrading to a sand filter. I don't know that I can afford a sand filter right now, but if I somehow could, would that likely speed up this process quite a bit? I can relate to that person's experience of watching the green matter shooting out from the return jet.

In another, someone that I've deemed to be reputable from my time on the site (long-time user or staff member I think) said to not forget this basic fact: filters don't kill algae; chlorine kills algae, then the filter removes it. That makes sense to me. I'm under the impression that algae is only alive when it's green. If both of those things are true, then why am I only seeing green (apparently) matter on my filter each time I hose it down? Is it capturing some live algae? Does it take quite awhile for the algae to turn brown/tan once it's dead, so it still appears green on my filter even though it's dead by that time?

Just read another thread where someone mentioned the need to brush and vacuum every day during the SLAM process. I realized then that I've not been doing that. I've vacuumed a handful of times, and brushed a handful of times, but have only done both on the same day once or twice that I can recall. Could the lack of that consistency explain why this is taking so long?

Finally - for now, at least - what would be the reasons to not try this guy's advice in this video that my wife sent me a short time ago? Aside from bleaching the liner, I mean - our liner was already bleached when we bought it used, so no worries there. If you don't want to watch the video - it's kind of long - he's basically saying that you need to hit the algae super hard all at once, just like you would hit a house fire. If your house is on fire you're not going to put out the fire in the kitchen one day, then tackle the living room the next day, and so on - you attack it all at the same time as much as possible. I don't recall how much chlorine he suggested but it would be way more than SLAM levels. It goes against TFP principles, I know that - but I'm tempted to try it if only to see what happens, because I'm spending sooo much time on this thing with very little apparent progress. The water appearance quality degradation the past 2 days really has me discouraged.

 

[IceShadow]

Do you have a way to just set it to circulate? You could keep the FC levels up, test as often as you can and keep them up, and just let the FC kill the algae. Once it goes from green to blue/grey and cloudy you could set it back to filter.

Adding extra FC has a good shot of damaging your pool surfaces and equipment. I wouldn’t recommend it.

 

[jessman1128]

Do you have a way to just set it to circulate?

I think so, yes. I think if I just take the filter cartridge out of its housing and turn the pump back on it would have that effect. The skimmer basket would catch any larger particles, and anything small enough to pass through the basket should be fine to pass through the pump. I might need to work from home for a few days and check up on it every hour or so. Once my test chemical refills arrive, that is - my current supply is about gone.

 

[aeh0603]

It sounds like you may just need to read the SLAM article again and make sure you are following all the steps. Brushing is a key step that you should do all least once a day. Algae can form a biofilm on surfaces which is basically a protective layer that chlorine can't get through. Brushing disrupts the biofilm and allows the chlorine to get in and kill the algea.

You are right that filters don't kill algae (chlorine does!), but if there is live green algae in the water, it will filter that too. The filter doesn't know the difference between live and dead. The main point of that phrase is that a filter cannot remove algae faster than it multiplies, you need to maintain adequate chlorine levels to kill the algea.

It sounds like your chlorine levels dropped a bit low and your progress went backwards a little. As frustrating as that is, if you continue to test FC and increase to SLAM level as often as possible (no more than once an hour, no less than 3 times a day), brush at least once a day, and stick with the SLAM process, it will work!

 

[CarolineM]

Also, take out any stairs or steps as algae hides in those. Give them a good cleaning with bleach and leave them out during the SLAM. Check your skimmer area for signs of algae and gunk also.

 

[jessman1128]

Also, take out any stairs or steps as algae hides in those.

I took the ladder out last week sometime when it occurred to me that the algae was hiding in the crevices of it. Haven't cleaned it yet but I think I'll need to disassemble it to give it a thorough cleaning.

I removed the filter cartridge this morning before heading into work. Also brushed the walls and floor and added enough bleach to raise FC back up to 12.

 

[mommark]

Also, take out any stairs or steps as algae hides in those. Give them a good cleaning with bleach and leave them out during the SLAM. Check your skimmer area for signs of algae and gunk also.

How do you take out steps when the pool and steps are filled with water? The stairs are beyond heavy.

 

[frogabog]

FWIW, the Intex cartridge filters and pumps are woefully undersized. The filter itself isn't the worst at filtering, but the pump likely is not moving enough water in general. This will hinder your SLAM.

If you can find another filter/pump used, you can double up, They're about $40 new as well. If you go that route, I have some tips and pics. We didn't do it in response to an algae bloom, but simply to maintain. In general however, I would suggest looking into upgrading to a higher flow pump which for Intex usually means upgrading to a sand filter. Those can also be found used locally. Sometimes even for free if you're willing to go disassemble and take home an unwanted pool.

Sand filters are known to be a little less effective on capturing dead algae and therefore may take a little longer to get to crystal clear, but they work ever so nicely for maintenance and you will never clean another cartridge filter again (ugh, I loathed spraying out those things! Such an annoying and WET job).

The guy in the video has the general idea, but he's advocating a one time application of what sounds like "somewhere around" SLAM levels which is not what we do here. SLAM level for your CYA level is going to do the same thing, but you're not overdoing it by dumping an arbitrary amount of chlorine based on zero information and expecting that one time application to do the job. His method also doesn't account for CYA, nor does it account for a massive increase in CYA by dumping 4-7 pounds of granular shock product in. 4-7 pounds also accounts for how many gallons? No one knows. Not even that guy.