Do I have an Ammonia problem?

[Ben_G]

I opened my 28,000 gallon pool last weekend and my CYA was well below 20. I thought it was at zero, because the water in the test cylinder didn’t seem cloudy at all even when full. I guess it might have been 5-10 or so, because after adding 7 pounds I’m now around 40.

I am trying to SLAM the pool now, but am using what seems like a ridiculous amount of Chlorine. I’m on the third day and have already been through 12 gallons of 12.5% and 8 gallons of 10% (the 12.5% is out of stock at my usual store).

The first couple of days, I’d check the FC three times a day, and was always down around 1.0-1.5 by the next check. I read about Ammonia, and the suggestion was to add and test frequently until the FC is stable. I’ve gone through the 8 gallons of 10% in just the last 6 hours or so and my FC is slowly creeping up (10.0 about 30 minutes after the last gallon went in). It still seems like it’s disappearing quickly though since 8 gallons should be enough to get my FC up to 28.0

Last summer I had trouble with my CYA disappearing too (and keeping my FC up) even after adding a bunch at opening. I had to add CYA several times even after I started supplementing liquid chlorine with tri-chlor pucks. So I think my pool might be susceptible to whatever the bacteria is that eats CYA.

I’m getting close to the point where I could have drained the pool and refilled it for the amount I’ve spent on chlorine (especially since I had to buy the 10% at a pool store, what a rip off...)

The one other thing is that my pool is in a wooded back yard, so I get a lot of organic material in it. I have an automatic pool cover, so the pool stays covered whenever it’s not in use, but still leaves and stuff manage to sneak in. Is all this chlorine just being chewed up by organics in the pool?

At least being stuck at home during quarantine makes SLAMing easier to do

 

[Richard320]

If you have ammonia, you'll see the FC drop almost instantly and the CC skyrocket.

I don't see any mention of CC. What is it?

 

[Ben_G]

I just tested it and it was 1.5, so certainly not sky high. The FC was Up to 13 now after adding another gallon earlier, so maybe I’m over the hump now.

 

[IceShadow]

You might have, but the copious amounts of FC killed it, perhaps. If it was bacteria that makes ammonia, check your CYA levels. They may have eaten it.

 

[Ben_G]

A follow up. This morning my FC was at 3.0 and my CC was at 5.0. So I’m clearly not done with the SLAM. I checked my CYA and it was 30. We did get a good rain last night, so I don’t know if the drop had something to do with that. I’ll test the CYA again tomorrow.

The water looks good other then the fine dirt/pollen that always settles to the bottom overnight. The robot will take care of that.

We’ll see how many gallons of chlorine I use today. Hopefully less then 8...

 

[Ben_G]

I ended up going through 6 gallons of 12.5% today. And I think I checked the levels one fewer time. Every time I checked, the FC was 2-3 and the CC was 4-5. I’d add enough chlorine to get back to 12 and repeat...

I’m up to 19 gallons of 12.5% and 8 gallons of 10% since Tuesday. This is the first time I’ve tried opening the pool myself (this will be my 3rd summer with it). Is this amount of Chlorine normal for a SLAM? In theory 3 gallons of 12.5% would raise my FC by 13, which is my SLAM target. I’ve added enough to go from zero to that target 8 times over. It’s not like my pool was a swamp to begin with, the water was pretty clear with only a slight tint of green when looking at the deep end.

 

[Donldson]

What you are doing right now isn't really a SLAM. It's removing this ammonia from the water so that you can then proceed with a typical SLAM Process.

Unfortunately there's nothing that can really be done about it, ammonia and chlorine can't really exist at the same time so it has to be removed before you can properly operate the pool. It's just an unfortunate thing that occasionally happens to a closed pool and there's no other way to handle it than a lot of chlorine.

 

[Richard320]

I ended up going through 6 gallons of 12.5% today. And I think I checked the levels one fewer time. Every time I checked, the FC was 2-3 and the CC was 4-5. I’d add enough chlorine to get back to 12 and repeat...

I’m up to 19 gallons of 12.5% and 8 gallons of 10% since Tuesday. This is the first time I’ve tried opening the pool myself (this will be my 3rd summer with it). Is this amount of Chlorine normal for a SLAM? In theory 3 gallons of 12.5% would raise my FC by 13, which is my SLAM target. I’ve added enough to go from zero to that target 8 times over. It’s not like my pool was a swamp to begin with, the water was pretty clear with only a slight tint of green when looking at the deep end.

No, this is not normal.... unless you're one of the lucky few who had the CYA break down into Ammonia. Then it's expected

 

[Ben_G]

Ok, I guess maybe I am one the “lucky” few. Is there anything I can do to avoid this in the future? If this happens again, is a drain and refill the way to go? My water is around $3 per thousand gallons, so a full refill would cost less then $100. I’ve spent well over that in Chlorine this week.

 

[mknauss]

Absolutely a water exchange would reduce the issue if you have it. You have a vinyl liner pool, so you cannot drain more than 18-24" at a time so that is an issue.
You can get an ammonia test kit from an aquarium store next spring. Test your water for ammonia. It takes right at 10X chlorine ppm to eliminate the ammonia ppm.

 

[fabsroman]

Absolutely a water exchange would reduce the issue if you have it. You have a vinyl liner pool, so you cannot drain more than 18-24" at a time so that is an issue.
You can get an ammonia test kit from an aquarium store next spring. Test your water for ammonia. It takes right at 10X chlorine ppm to eliminate the ammonia ppm.

Yep, I had an ammonia issue when we opened up the pool. Poolgate helped me with opening the pool and figuring out my water parameters. Ammonia was above 8 ppm according to my aquarium test kit (highest it will measure since all the fish would be dead already) and dumping in 10 gallons of 10% chlorine did not move it below 8 ppm. My wife and I ran a mini test with a small sample of pool water and adding a little bit of chlorine at a time and then testing. We determined that we needed another 40 gallons of 10% chlorine to get rid of the ammonia and that is exactly what it took. Went out and bought 48 more gallons of chlorine and now we have 8 gallons left over.

Slowly but surely, I am getting the pool where it needs to be. A before and after pic and then the kids enjoying the freezing water on May 3rd. They spent 3 hours in the pool.

 

[dianedebuda]

What test kit did you use? Thinking about getting an API drop kit just as a heads up for increased chlorine needs before starting my swamp SLAM.

 

[Ben_G]

Would you mind giving a little bit more detailed explanation of how exactly you did your “mini test”? What amount did you test with and how did you scale it up to the whole pool?

it’d be nice to not have to keep running out to the store for more chlorine every day...

 

[Ben_G]

I’m hoping I’m not jumping the gun here, but I may have finally gotten all the Ammonia. I’ve hit the pool with 4 more gallons of 12.5% today. I just tested it an hour after adding 2 gallons, and my FC was at 16.0 and CC was 0! My CYA is still 30, so I overshot my SLAM target a bit. That’s probably due to my impatience. I’ll check it again in a few hours, and then probably try an OCLT.

I’m currently at 19 gallons of 12.5% and 8 gallons of 10%, which adds up to 111 ppm for my pool. I still have 6 gallons of 12.5% left, so hopefully that can get me through this SLAM.

 

[Ben_G]

Just a final week later follow-up. The pool did pass the OCLT and the FC has been slowly drifting down (7.5 today) while the CC has been either 0 or 0.5. I just need some sunnier days to Lee the cover open to burn off that last bit of FC. My CYA has been steady at 30 as well, so I think I may have finally gotten this thing under control.

I did get an Ammonia test from the pet store just in case this happens again. It only goes to 8 ppm (it’s a color match test similar to a basic chlorine or pH test). Based on the 10-1 ratio posted earlier, it looks like I was around 10 ppm Ammonia. I assume if it got over 8 again, I could dilute the pool water half and half with tap water and double my test result to get an estimate though.

Thanks again for all the help!

 

[Richard320]

Pictures or it didn't happen.