SLAM Advice - 2 Weeks and 100L of CL

mooseau

Bronze Supporter
Jan 24, 2020
72
Sydney's Northern Beaches
Pool Size
82500
Surface
Plaster
Chlorine
Salt Water Generator
Hello!

I've been slamming for over two weeks now. The pool is finally crystal clear, but I still am consuming 7L of CL a day. Chlorine levels over the last two weeks have been around 26, recently bumped to 31.5 since it is mustard algae. It's been close to 31 for a few days now. And I do have DE in the filter.

I'm pretty sure it's mustard algae because in the day it's fine brownish dust, and in the morning it's white. I don't think it's pollen because I don't see it on my pool tiles.

I'm off to buy more chlorine.

FC: 31.5
CYA: 60
CC: 2.5
 
Even if you do have Mustard Algae, you shouldn't be losing a lot of chlorine each day unless there is some very active algae hiding somewhere. Can you post a pic or two of your pool from different angles so that we can get a better idea of what you have there?
 
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When was the last time your cya was tesred? Could be lower than you think and the hot sunny days we have had the last few weeks may be consuming your FC.
just a thought..
 
Cya was tested a week ago. The smell of chloramides is strong. Even if cya was low, that wouldn't explain cc of 2.5. A full balance was 2 and a half weeks ago.

I also see the swg is badly scaled. I cleaned it a month ago, never seen it this bad. Would that imply PH is too high? I obviously cannot test.

And after just two hours, I can see more algae. When I sweep, it's a combination of brown/white.

I'm wondering to let it drop to 10PPM and rebalance to see what is going on . . .
 

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Hey Moose !!

The CCs are telling the story, and the smells are backing it up IMO.

Its time for a full blown scavanger hunt. Every inch is suspect until its proven otherwise. The light niche, weir door, all up in the skimmer, all of it. Deep clean the filter too.

If you chose to let it drift down, you won't lose any ground in the battle, its more like hitting the pause button. Algae wont overtake you as you drift down and are a 15 (?) FC. I'd want no CCs first.
 
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Moose, you mention a few things that caught my attention:
- A full balance 2 1/2 weeks ago implies that you may not be testing your own water. Please confirm who or how your water is tested. The lack of proper (or consistent) testing is the #1 problem for most pool owners who struggle with this issue.
- Scale on the SWG could be from a high CH, pH, and/or TA, combined with elevated water temp. All four of those contribute to scale, but no doubt pH has the most immediate and significant impact on scale. That has no bearing on the algae though.
- In your area, folks rely on reliable test kits from Clear Choice labs (aka Taylor K-2006C equivalent). That is the only way to actually maintain an accurate FC and CYA during the SLAM Process. What kit do you have?
- The chloramine smell is most likely all that residual organic material being burned off. If you haven't used any other MPS-type chlorinating products, then it is al from residual algae being killed, but you're not done. The SLAM Process should be followed closely until you pass all 3 criteria..
 
*sigh*. OK, I'll do that tonight. Brush everything thing down. Good point about the lights. I will remove them and brush. And actually, there is a shelf under the fountain which isn't always scrubbed.

Are you saying that even though there is a high enough level of CL, mustard algae can thrive?

Interestingly, in the last 4 hours, the pool is a bit more cloudy, slightly off crystal clear. Despite another 7l.

I haven't tried opening the sand filter; I guess I need to do that. It will have to wait for the weekend.
 
Moose, you mention a few things that caught my attention:
- A full balance 2 1/2 weeks ago implies that you may not be testing your own water. Please confirm who or how your water is tested. The lack of proper (or consistent) testing is the #1 problem for most pool owners who struggle with this issue.
- Scale on the SWG could be from a high CH, pH, and/or TA, combined with elevated water temp. All four of those contribute to scale, but no doubt pH has the most immediate and significant impact on scale. That has no bearing on the algae though.
- In your area, folks rely on reliable test kits from Clear Choice labs (aka Taylor K-2006C equivalent). That is the only way to actually maintain an accurate FC and CYA during the SLAM Process. What kit do you have?
- The chloramine smell is most likely all that residual organic material being burned off. If you haven't used any other MPS-type chlorinating products, then it is al from residual algae being killed, but you're not done. The SLAM Process should be followed closely until you pass all 3 criteria..
I say full balance two weeks ago because that is when I started my slam. I certainly am using Clear Choice Labs testing. I know Brett :)

Yeah, temps have been really high (30s celcuis, 90s F?).

The only thing I've tested since is CYA a week ago, and the ongoing chlorine tests.

Is there anything else I should/can test during a SLAM?
 
Good point about the lights. I will remove them and brush. And actually, there is a shelf under the fountain which isn't always scrubbed.
Every. Last. Inch. (y) run the fountain twice a day to make sure its getting flushed too. it has hid in pain sight many many times before yours. It looks like you have no ladder, but thats another biggie. Each rail can hold a couple gallons of old water and reintroduce the nasties.
Are you saying that even though there is a high enough level of CL, mustard algae can thrive
Not neccesarily 'thrive' per se, but removing algae is a process and it takes time. Mustard algae is usualky a 24 hour kill after a SLAM, but no 2 Slams are the same, so your milage may vary.
Is there anything else I should/can test during a SLAM
Brush and vac at least once a day. FC kills it and it drops to the floor. It needs to be stirred up so the filter can grab it, or vac'd out to waste. You can cheat a little by brushing to a general area and then only having to vac a small area. It takes a few tries brushing, let it settle. Brush again..... but brushing is pretty quick so its still pretty easy. And it saves a good chunk of waste water.
 
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What is the impact if I don't vac (i.e. I don't have one)? I'm assuming just a dirty pool floor and no impact on killing the algae.
Vacuuming removes the dead bodies lol 😂 but seriously the dead algae & other organics need to come out - they are just more work for your fc.

This also can put less strain on your filter if u have the ability to vac to waste for heavy debris.
I’m a clean floor fanatic- how do you stand not having one?
A cheapo basic vac head, hose & pole shouldn’t run you too much moola $$
Have u put anything besides these recommended chemicals👇in the pool?
Like MPS perhaps?
That level of cc’s is concerning…
 
I have a Jetvac. It cleans the floor very well for me. I've never had enough floor waste to justify vac to waste. The only issue was the storm 3 weeks ago. And maybe therefore I got into trouble. There were so many leaves, it took about a week and a half to clear.

This is the first time I've heard of MPS. No, never used it. Only liquid chlorine and SWG.
 
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I have a Jetvac. It cleans the floor very well for me. I've never had enough floor waste to justify vac to waste. The only issue was the storm 3 weeks ago. And maybe therefore I got into trouble. There were so many leaves, it took about a week and a half to clear.

This is the first time I've heard of MPS. No, never used it. Only liquid chlorine and SWG.
That cleaner is sufficient so long as u are brushing as well. The brushing disrupts the biofilms that protect the algae from chlorine. It’s an all important step.

For a minute there I thought u never vac’d at all ! My ocd feels better now 🤣

Also as far as mustard algae goes - you must completely pass ALL 3 end of slam criteria before increasing to ma levels for 24 hrs & following the ma protocol. 👇

You’re not quite there. You just gotta be like Dory & keep going 🐠. It’s more of the final blow when algae is almost down for the count.

You’re on a search & destroy mission. As you complete it be sure to test & replenish fc as often as possible (just not more than once per hour) so you stay at slam level for your cya as much as possible. Dipping below gives algae a leg up & can really prolong a slam - going above for long periods risks damage to surfaces & equipment & wastes precious bleach to the sun ☀️.

Go get em’ 🦠
 
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Thanks for the advice. I've vigorously scrubbed a few times a day and have left my equipment at the shallow end. The advice on clearing the fountain was sound. There was algae in there and it came tumbling out. As a result, I've also discovered I have a spa bubbler, which I didn't know! I cleared that out, too.

But I'm still not getting any headway. On the advice of a pool warehouse (not a pool shop), I'm to use LoChlor Algae KnockOut. Apparently, Sydney Mustard Algae is so insidious that it is the only way. And I have to concur.

The effect is amazing. I have massive plumes of white (dead) algae, and the pool is really clearing up. Is Benzalkonium chloride the same as PolyQuat? I don't think there is PolyQuat in Australia.

This now raises the question of economics. SLAMing for three weeks is slow, cost-ineffective compared to the Algae KnockOut, not to mention the complaints I'm getting about a highly chlorinated pool.

I can't help but ask if in this case that SLAM is not the correct solution here.
 
I doubt your slam would have taken quite this long if you had found & cleared the hidden offenders on day 1.
As @mknauss said algeacides aren’t the answer to an algea bloom & relying on them can not only get expensive but also mask the underlying issues like inadequate fc as well as cause a host of other issues. They are more for insurance/preventative.
The active ingredient in what you mentioned has been known to cause foaming & even form chunks in a salt water pool 😩
 
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I doubt your slam would have taken quite this long if you had found & cleared the hidden offenders on day 1.
As @mknauss said algeacides aren’t the answer to an algea bloom & relying on them can not only get expensive but also mask the underlying issues like inadequate fc as well as cause a host of other issues. They are more for insurance/preventative.
The active ingredient in what you mentioned has been known to cause foaming & even form chunks in a salt water pool 😩
So, if I understand what everyone is saying, actively sweeping the entire pool every day disturbs the buggers which would otherwise be resistant to chlorine. By not sweeping properly, or running the fountain, the algae sticks around.

I can get that, i haven't been properly sweeping during the slam. Under my fountain especially, which is where i see the most.

FYI as a result of the knock out, CC has dropped from 2.5 to 1.0, and daily FC consumption has dropped from 7ppm per day to 4ppm. The chloride smell is also gone.

It is still at SLAM levels having dropped from mustard level. And I've taken your brushing advice, doing it three times a day, even if I have to wade in the pool.
 
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So, if I understand what everyone is saying, actively sweeping the entire pool every day disturbs the buggers which would otherwise be resistant to chlorine. By not sweeping properly, or running the fountain, the algae sticks around.
Exactly. Algae grows a biofilm to protect it from harsh environments. You need to disturb it’s protection so the FC can get to the algae itself. It’s not a one and done, there may be layers and layers. Each swipe makes you one closer and stirs up whatever you did get to be killed in the water.

Just like the Slam itself, it’s a ‘process’.

You got this.
 
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Thanks. I've been thoroughly sweeping 4x a day. It's disheartening to always see new brown "dust", but the quantity has decreased. Pool is crystal clear, and CC is now down to 0.5.

I'm assuming this isn't considered clear since I still see debris, be it brown, or white, when I sweep.
 
I'm assuming this isn't considered clear since I still see debris, be it brown, or white, when I sweep
Correct. But. I'd take being at that stage anytime. The green swamp stage SUCKS. So try to remember that when your spirits get low. You couldn't doing all this *and* have a swamp to backwash. :)
 
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