Trouble with SLAMming - been doing this for years and never had this happen

kisaacs

Member
May 25, 2014
12
MA
Hi all,

I've been an avid reader and follower of your methods for about 7 years. I haven't put anything but liquid shock, borax, baking soda, and muriatic in my pool in that time. This year, I"m stuck and frustrated.

We've had the pool open for 12 days. In that time, I've been SLAMming it constantly.
ph = 7.2
CYA = 35
Chlorine consistently above 16
vacumming, brushing walls daily

12 days later, still green and cloudy. Every single other time I've done this, I've had the pool go from green to blue and cloudy in 2-3 days, and then take about a week to get to clear. This time, I just can't get the algae to die, and I have no idea why. What am I missing?

Thanks so much for any ideas. I'm really stumped, and the methods on this site have never failed me.
 

kisaacs

Member
May 25, 2014
12
MA
Well that is no good. What type of filter do you have? What is your FC dropping to after a few hours?
Sand filter, new sand and just repaired this year as the internal part broke and it was shooting sand into the pool late last year. We closed the pool and didn't fix it til this spring.

FC drops really slowly, furthering the mystery. If it were eating algae, I'd expect it to drop dramatically consistently, but it doesn't. I usually test at 8am and then again at noon and again in the evening. Between tests it usually drops 1-2 ppm. I don't know the overnight loss because honestly I haven't been paying attention to that as I wake up every morning, look out the window and see green.

Some googling and some other question asking has led me to start asking - could it be copper?

When I opened it this year, it was down to 18" or so of water. The cover had sank in significantly. No big deal, I thought. I just filled it the way I always do - from the hose. So it's about 65% new water. Is it possible there's copper in the water? I swear the pool is greener at the end of the day than it is in the morning. I'm so confused.
 

kisaacs

Member
May 25, 2014
12
MA
Have you vacuumed the pool? There may be organic debris hidden under all that green water. Try running a net across the floor and see if anything comes up. No telling what fell into the pool after your cover went toes up...
Yes. Skimmed the bottom and have vacuumed to waste several times.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,905
Laughlin, NV
Metals can be the color but not the cloudiness.
Copper is possible, but you had to add it. It is not prevalent in water supply systems. Iron is also a possibility.

Have you been using copper sources like algaecides, shock and pucks with copper, a heater (none shown in your signature)?
 

kisaacs

Member
May 25, 2014
12
MA
Metals can be the color but not the cloudiness.
Copper is possible, but you had to add it. It is not prevalent in water supply systems. Iron is also a possibility.

Have you been using copper sources like algaecides, shock and pucks with copper, a heater (none shown in your signature)?
No copper sources at all as far as I know, unless my liquid shock has copper in it. I doubt it, but I'll double check the ingredients. No pucks, no algaecides, no heater. I know better than to put any of that junk in the pool!

I just filled 65% of the pool with fresh water from the tap, so exchanging the water would just be the same kind of water I just put in.
 

Daltex

Well-known member
Jul 31, 2012
54
Dallas
I've heard of this before. Try putting a little DE in the filter and keep backwashing as it starts the pressure climb. I would use 10% increase if you want to get it cleared fast.

You may have a filtration issue so if you see plumbs of white DE coming out of the supply jets then I would take apart the filter to see what's up.
 

kisaacs

Member
May 25, 2014
12
MA
I've heard of this before. Try putting a little DE in the filter and keep backwashing as it starts the pressure climb. I would use 10% increase if you want to get it cleared fast.

You may have a filtration issue so if you see plumbs of white DE coming out of the supply jets then I would take apart the filter to see what's up.
Thanks. I had heard of using that too, and I think it's worth a try. Can you clarify what you mean by "use a 10% increase if you want to get it cleared fast"? Does that mean put 10% DE in or let the pressure increase 10%? From what I've read other places, I want to use about 1-2 cups of DE. Is that what you'd recommend?
 

kisaacs

Member
May 25, 2014
12
MA
I don't know why the people here smarter than I haven't asked you to do an overnight chlorine loss test. Daytime loss can be from the sun.
Agree. I'm going to do that tonight. I should have done it already before asking, but knowing I wasn't anywhere near clear, I hadn't been keeping good track of that number, as it's usually the last hurdle to clear before I'm done SLAMming. I'll do it tonight and report back.

I've just never seen a pool stay green with the amount of chlorine I've put in it. It's a completely different pattern than I've seen for the last 7 years, which is why I asked without having those test results
 

Daltex

Well-known member
Jul 31, 2012
54
Dallas
10% pressure increase. You can go higher but the flow will drop off so you will have slower cleaning. I wouldn't set an alarm to check it in the middle of the night but was just saying as a general rule.

I have always used a DE filter so you would have to get a sand filter person to help with the amount. I would assume a couple of scoops would be good.
 
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Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,932
San Dimas, CA (LA County)
Thanks. I had heard of using that too, and I think it's worth a try. Can you clarify what you mean by "use a 10% increase if you want to get it cleared fast"? Does that mean put 10% DE in or let the pressure increase 10%? From what I've read other places, I want to use about 1-2 cups of DE. Is that what you'd recommend?
The link for the How-to is also at the bottom of the SLAM Process

 
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kisaacs

Member
May 25, 2014
12
MA
Okay, morning update. Overnight Free Chlorine Test yielded a result of a loss of 3ppm overnight. So, there's still some organic matter in there for sure.

Adding DE to the filter has increased filtration. As of this morning I can see the bottom, but it still has a greenish hue. I'd say it is finally improving, though slowly. Apparently the magic was asking for help. I'll continue to update to see if that greenish hue dissipates over the next few days. Fingers crossed, and keep on SLAMming
 

mmcwhorter

Silver Supporter
Bronze Supporter
Jul 13, 2015
195
Huntingtown, MD
I have used small amounts of DE in my Hayward sand filter due to similar problems with good effect. Curious: How did it work for you? The forum has not heard back from you. Is everything OK?