SLAMming a green swamp, but with complications

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survivalcar

0
Jun 9, 2018
58
Northampton, MA
I've SLAMMED my own pool in years past and this week I'm trying to help some friends with their pool, since I've had some experience and also I've got a little free time. Please see attached photos.

I've read this Turning Your Green Swamp Back into a Sparkling Oasis
and I know what I have to do but there are a couple complications:

1. I live about 20 miles away from this pool and can't spend all day every day there, so I have to figure out the most important/efficient times of the day to get there.

2. There's an air leak somewhere (the owner thinks maybe a cracked PVC under the concrete?) such that the pump is pulling a lot of air as well as water. I don't know how this is going to affect the SLAM process but I suspect everything about it will be less efficient - you can see the air in the pump trap during backwashing, rinsing, and just regular pump operation. There's only one intake (water-level skimmer) and one return (a jet kind of opposite the skimmer). There's a chlorinator attached to the pump. It has some big chlorine tabs in it but there is 0 FC reading.

Since I didn't have any LC on Day 1 (yesterday) I put in some product from Walmart that was advertised as a combination shock/algaecide. The shock component is cal-hypo and it's a powder in small bags. I backwashed, rinsed, and put about 150% of the recommended amount in the pool, along with 2 bottles of Clorox bleach (5%?) that the owner had on hand. I don't know if the Cal-hypo would show up on a chlorine test but I took my Taylor kit over today and the FC reading was 0.

Right after that I put in enough 12% LC to raise the SLAM FC level to 20ppm (based on the CYA of 50), then brushed the floor and walls, which I can't see (see photos). I had to leave about 15 minutes after that and I checked the chlorine and it was at 10ppm. I don't know if this is because the algae ate it or because the air-leaking pump hadn't distributed it throughout the pool yet.

A couple questions - should I bother with an algaecide? I saw a couple different products at Walmart on my way home tonight and it seems there's different kinds. If I should use an algaecide, which one?

If I have a couple hours a day to get over there, does it make sense to do it at the end of the day, so the LC can do its thing without any sunlight on it?

I'll know the green stuff is dead when the FC holds, right? I was planning on vacuuming with the pump set to WASTE and then refilling the pool with a hose, which I did at my own pool a couple years ago. Their pool is much smaller and, even though the pump suction isn't too strong, it won't take too long to replace the water that gets sucked out with water from the hose (tap water).

Anyone have any thoughts about the air in the pump, the algaecide, and the time of day best suited to spend some time there? Anything else I'm not thinking of?

Thanks in advance for this and for all the help this fantastic place has given me

Chris

FC 10
CYA 50
The owner says the pool is 20,000 gallons but it looks more like 15,000 to me
 

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It would be best to do a healthy water exchange.

No algaecides. No powders, etc.

For the suction side leak, check the pump basket lid. Inspect/lube the gasket really well. Many times that is the source of the leak. You will struggle to cure this and maintain it with a large suction side leak.

Once you get some of the above done, have the pool owner add liquid chlorine in the am and at noon. Go over in late afternoon to attack it and get chlorine in it for overnight. Better is to have them get their own test kit and learn.
 
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Do you mean drain the pool and have it refilled with clean water? Are you saying that based on the photos? Or the air leak in the pump?

The owner has had someone look into the air leak and I think they're fairly certain the leak isn't coming from the pump trap lid. I will bring that up with him again.

I should clarify that the skimmer is taking in water, and the return is working, although with air bubbles. I should also point out that I have the same pump at my house and the suction we get on the vacuum, with no air leaks and a longer hose, and also while pulling in from 2 other intakes (another skimmer and the bottom intake) is still much stronger than at his pool.

My main fear was that the problem with the pump would make the SLAM a non-starter. I had hoped it would still work but maybe just slower than I could expect with a fully healthy pump.

The owner is usually only home on weekends, and I have time to help him, even a couple long days to get it started. Do you think it's not going to work even if I stay there all day and keep topping off the pool?

Thanks again for your help

Chris
 
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By looking at the water there is a significant amount of organics to kill. The foam is also concerning but that could be the algaecide.
The air in the pump is harming its efficiency. To clear a pool, you need to pull in the solids to filter them out. So that is an issue.
Does the vac hook up in the skimmer or a vac port?
 
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Going forward never use Clorox bleach. The label says it contains Cloromax Technology which is polymers that are not suitable for pools. Some of the foaming may be coming from the polymers.
 
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mknauss said:
By looking at the water there is a significant amount of organics to kill. The foam is also concerning but that could be the algaecide.
The air in the pump is harming its efficiency. To clear a pool, you need to pull in the solids to filter them out. So that is an issue.
Does the vac hook up in the skimmer or a vac port?
Click to expand...

There is no vacuum intake other than the skimmer. I don't think there's a whole lot of large particulate stuff in the pool, at least not that I could feel while pushing around the brush. And nothing big came up while brushing. It's just like really thick pea soup.

So my dilemma is whether to spend his money on a lot of LC to kill the green stuff. I don't mind sitting with it while it levels off for a couple days, even if it takes a couple days longer to vacuum it clean. But if I buy a bunch of LC and it doesn't work at all because of the pump, then that would be a drag.

It does seem to me that when I SLAMMED my pool, there was a lot more buildup on the bottom and it looked less like it was in solution. Will the stuff settle to the bottom once it's dead and so it'll be easy to remove by vacuuming on WASTE?
 
Whether the algae settles to the bottom or not seems to be indeterminate. Some folks see that, others do not. Filtering is best way. And with a compromised pool suction, that is an issue.

Is the pool owner willing to temporarily run a line from the pump to the pool for a suction? Would not be pretty, and you would lose the skimmer effect. So take that into account.
 
mknauss said:
Whether the algae settles to the bottom or not seems to be indeterminate. Some folks see that, others do not. Filtering is best way. And with a compromised pool suction, that is an issue.

Is the pool owner willing to temporarily run a line from the pump to the pool for a suction? Would not be pretty, and you would lose the skimmer effect. So take that into account.
Click to expand...

I'm sure he's totally fine with anything I can figure out that will work. I'm just wary of spending his money on LC and then having it not work because of the pump.

I'm not sure what you mean though. Like connect the vacuum hose directly to the pump? (I do own a submersible pump that comes in handy at home for emptying the hot tub, for example. But the only adapter I have for that thing fits a garden hose).
 
I was thinking of running a 2" PVC line from the pump suction to the pool, bypassing the skimmer. That would eliminate the air issue, if at the skimmer.
 

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mknauss said:
I was thinking of running a 2" PVC line from the pump suction to the pool, bypassing the skimmer. That would eliminate the air issue, if at the skimmer.
Click to expand...

That would involve removing the metal doohickey that holds whatever's there now in place, and cutting up some PVC, putting it together with epoxy, and then somehow fashioning an adapter that the vacuum hose could go onto? Or just submerge the other end of the PVC so it's sucking water directly?

The pump is right on the other side of the fence, maybe about 10 feet from the pool. Maybe even a short piece of PVC and then an adapter that the hose could fit onto? I've never done anything like that before. Maybe it's not as hard as it sounds.
 
If only 10', a straight run of pvc would be best. 90 down in to the pool 6 inches or so.
 
You could use this if you have to make a few bends and it would prevent you from having to cut and glue pipe:

Amazon.com : Sealproof 2" Dia Flexible PVC Pipe, Pool and Spa Hose, Schedule 40 Tubing, Made in USA, 2-Inch, 25 FT, White : Gateway

Amazon.com : Sealproof 2" Dia Flexible PVC Pipe, Pool and Spa Hose, Schedule 40 Tubing, Made in USA, 2-Inch, 25 FT, White : Gateway
www.amazon.com

Then one of these male fittings with a hose clamp to connect to your pump and you should be good to go:

Spears 1436 Series PVC Tube Fitting, Adapter, Schedule 40, Gray, 2" Barbed x NPT Male: Amazon.com: Industrial & Scientific

Spears 1436 Series PVC Tube Fitting, Adapter, Schedule 40, Gray, 2" Barbed x NPT Male: Amazon.com: Industrial & Scientific
www.amazon.com
 
Hey guys. I wanted to post a before/after here to see how well this cleared up by slamming. I rigged a regular vacuum hose to the pump intake and submerged it in the pool by tying it to a brick. Did the job in about 4 days.

I wasn't there over the weekend and the owner added chlorine but not enough. I went over today and FC read 10ppm but when I checked the CC it was 0.

I threw enough chlorine in the pool to bring it back up to 20 (based on CYA of 50) and I'm heading back tomorrow. I didn't check the TAC but I did check the pH, out of curiosity and knowing that it would be way out of whack because of the SLAM. It wasn't any color enough to read, so I guess it's insanely low.

Two questions: even though the FC wasn't at 20 (not my fault!) when I took the CC reading, the CC still reads 0. Does this mean I can move beyond the SLAM and do an overnight FC loss test, or do I have to check the CC reading when the FC is at 20? Seems to me if there's no CC then it's done SLAMming, yes?

You can see to the bottom of the pool (about 8 feet down) but it's still a tiny bit cloudy, and I'm wondering if the reason for that is the pH/TAC.

Also the pH is insanely low but I think I have to adjust the TAC before I can deal with the pH, right? There are brown stains on the bottom of the pool that look like mineral stains, that the owner says weren't there last year. I read in an article on here that those stains could be the result of pH/TAC problems. And if not, I've dealt with my own metal stains using Vitamin C so I think I know what to do if the TAC/pH adjustments don't fix it. Unless of course you have other suggestions!

Just looking for guidance about what to deal with first and whether I'm done SLAMming enough to do the overnight test.

Thanks again for everything

C


mknauss said:
If only 10', a straight run of pvc would be best. 90 down in to the pool 6 inches or so.
Click to expand...
 

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I haven’t seen any number for pH or TA but TA won’t affect water clarity and pH gave you weird color because that high chlorine concentration actually oxidized pH pigment. Your actual pH is probably a little higher than what it was before SLAM but you can’t test it before FC falls under 10
 
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Fast7 said:
I haven’t seen any number for pH or TA but TA won’t affect water clarity and pH gave you weird color because that high chlorine concentration actually oxidized pH pigment. Your actual pH is probably a little higher than what it was before SLAM but you can’t test it before FC falls under 10
Click to expand...

Thanks again to everyone for your help with this. Discovered out of the blue today that the reason the FC was dropping so much was the CYA went from 50 to 0. I thought it was very uncommon for this to happen, no? When the pool was still green I quadruple-checked the CYA every time I checked the pool, because it seemed unlikely to me that it would read 50 after a New England winter with all that slime on it.

I kept checking it pretty much up until the SLAM cleared the pool water, and I realize now I should have checked it well into this week.

I added CYA and we're doing the OCLT tonight. I picked up TAC to add tomorrow if the OCLT passes.

Incidentally, does anyone care to take a guess how many gallons the pool in the photo is? I've been calculating the amount of chlorine to add based on 20,000 gallons, which is what the owner told me, and when I added chlorine it seemed to go up by the right amount. I showed the photos of the pool to my local pool guys and they said nowhere near that, most likely 10,000 but maybe 15,000. It's hard to tell from the photos but it's about 8 feet deep in the deep end and maybe 3 feet deep in the shallow end.

Any thoughts appreciated.

Thanks

Chris

FC 22
CC 0
pH under 7, below the shades on the tube
TAC 40
CH 80
CYA 50
 
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