Still green....SLAM'ing help

Spa Owner

In The Industry
Jul 14, 2017
162
Victoria Park, Antipodean
Thank you both. I've NEVER had high PH. Actually, I've frequently aerated to keep it from dropping too low. Was shocked to see it off the chart high when I got home.
Classic algal bloom sign...

Algae are plants.

Plants breathe carbon dioxide. Algae are no different.

What actually happens is the algae starts and takes up all the freely available carbon dioxide to live on. Fairly quickly this is exhausted so it starts to break the bicarbonate ion into carbon dioxide gas and the outcome of this reaction is hydroxide which puts upwards pressure on the pH. Significant upwards pressure.

There is several other phases of an algal bloom and some of the chemical reactions are astounding, in some cases you can see this in small black flecks on the algal mass the small black flecks are carbon.

This is why pH 'off the charts' in cloudy water is a strong indication of algal bloom in progress. A typical algal bloom result might look like:

Cl 0
pH >8.0
TA 20

This seems illogical as low TA and high pH don't go together. This is in fact not correct. The TA method measures only the bicarbonate and some other minor chemical species. At pH 8.1 carbonate is the predominant species with a strong follow on from hydroxide and consequently not accurately reflected in the test results.

HTH
 

duraleigh

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In The Industry
Apr 1, 2007
32,152
Sebring, Florida
Well, algae is not exactly a plant....from quora.com......Algae are able to photosynthesize, a key characteristic of plants, but lack true roots, stems, or leaves so are not considered plants.

I will not hijack the thread but can you cite some sources for your chemistry? Why don't you PM me to keep the thread on track.
 

Veccster

Bronze Supporter
Aug 30, 2016
357
Pittsburgh PA
Interesting...thank you both for your contribution.

Meanwhile...I'm still here with a cloudy pool :(
I cleaned the filter this morning. FC is not dropping too quickly anymore so I think I've killed off all the algae. CC was 1 this morning so I'm not done slamming yet. I'll keep the FC at 27-29 until I'm cleared up and can pass the overnight CL drop test.

Just wish it would hurry up!
 

JimMarshall

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TFP Guide
Jun 5, 2017
755
Oil City PA
I would run your pump on high veccster, or at least speed 4. Will increase your electric bill a bit but you want to keep that water moving.
 

Veccster

Bronze Supporter
Aug 30, 2016
357
Pittsburgh PA
Thanks. Yes, I have had it cranked up for a bit. I'm giving it a break right now and running at 2300. I had it running at 2800 for about 18hrs. I'll bump it back up tonight.
 

Veccster

Bronze Supporter
Aug 30, 2016
357
Pittsburgh PA
Question for you...

If the cloudy pool is because of all the dead algae floating around, why should I keep the pump running?

Why not shut it down and keep the water still - allowing the dead algae to sink to bottom, and then sweep it up? Seems more efficient than trying to turn over all of the water.

Thoughts?
 

mknauss

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May 3, 2014
20,353
Laughlin, NV
Give it a try. Normally dead algae is very light and the minute you disturb the water it 'poofs' away.
 

DirtyRat91

Well-known member
Jun 5, 2013
137
Agreed, let your pump do all the hard work. Keep that algae in suspension so it can keep rolling through the filter. If in theory all the cloudy dead algae does even settle given enough unturbulent still water time, the moment you lower the pool vacuum wand into the pool it will all swirl into the pool. Job himself wouldn't be patient enough to try to creep the vacuum around the pool in an attempt to keep the crud on the floor.

Having cleared a tricky murky mess this year, I can attest that it takes patience. In an impatient attempt to force things along, I assumed that my sand filter was low on sand, so I added 100 lbs more. Not sure that helped or not, but it gave the placebo effect as my pool shortly cleared up afterward. This is NOT official TFP advice, so tread lightly. During my SLAM the color gave way to a blue hue, and my FC demand dropped off, passed the OCLT, but the pool was still cloudy. Using the theory that the baddies were eliminated, it was just wait for the filter to clear up the water time, I relaxed on the FC, dropping away from SLAM levels. The water did clear up and I've been trouble free since then.

But I'm pretty sure the standard advice is keep SLAMing until it's clean as can be. I've found the knowledge from the forum to be invaluable, but for best results, stick with the proven advice from the pros.
 

Glofton

Well-known member
Jul 3, 2018
62
Loganville Ga
Be patient, I know its hard. My pool didnt look nearly as bad as yours did at the start of the SLAM and my SLAM lasted almost 14 days. Stick with it and good luck!
 

Spa Owner

In The Industry
Jul 14, 2017
162
Victoria Park, Antipodean
Thanks. Yes, I have had it cranked up for a bit. I'm giving it a break right now and running at 2300. I had it running at 2800 for about 18hrs. I'll bump it back up tonight.
If the pool is still cloudy I would be inclined to stay at 2300. The flow rate through the filter is well within the manufacturers guidelines at the 2300 speed and slow enough to allow the filter to work.

There is a vague chance the particulates are smaller than the cartridge can capture. In this case a small amount of D.E. powder (if available) can help to improve the filter performance.

A final note on cartridge filters, really think about replacing the cartridge internal filters about every 24 months. Older than this they are usually starting to breakdown and not perform well.
 

mknauss

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May 3, 2014
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Laughlin, NV
It is not advisable to add DE to a cartridge filter. In the distant past some manufacturers stated it could be done but none that I know of still recommend it. Cartridge filters do a sufficient job of filtering out any fines we get in a pool.

My cartridge filters are 4 years old. And still filter like new.
 

Veccster

Bronze Supporter
Aug 30, 2016
357
Pittsburgh PA
Still cloudy...

Though my pH is reading 7.3, is there a chance it's actually much higher? Maybe the high CL level is giving me a false reading?

Maybe that's causing the cloudiness?
 

mknauss

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May 3, 2014
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Laughlin, NV
You can. If you started the SLAM as it is advised at a pH of 7.2 or so, then there should not be an issue. Unless you have added additional chemicals or large amounts of fill water that could have changed your pH.
 

JimMarshall

Gold Supporter
TFP Guide
Jun 5, 2017
755
Oil City PA
Veccster, the High FC causes artificially high pH reading as Marty stated.

Do you have full test results? When is the last time you broke down your filter and cleaned the cartridges? What is your current filter pressure vs your clean filter pressure?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
20,353
Laughlin, NV
If you are following the SLAM Process process your FC should be at 24 ppm. Are you testing every couple hours and adding liquid chlorine to keep your FC at that level?