High FC but still cloudy

[Allykeep]

Hi! Looking for guidance on getting our pool crystal clear. Checked levels this evening and got the following results:
FC 7
CC 0.5
TC 7.5
pH 7.8
TA 100
CYA 20
Calcium hardness 175

Plan to add stabilizer tomorrow and calcium chloride to increase CH. My struggle is that the pool will be fairly clear but has a layer of sediment on the bottom. Once that gets stirred up the pool is very cloudy. The filters run approximately 8hrs/day and we have backwashed it once a week for the past several weeks to get rid of the sediment. I get the pool being cloudy with low chlorine levels but that’s not the case here. We have vacuumed (with a shopvac) to get the thick layers of sediment and have a Polaris running at least 6hrs/day. Any guidance on levels and how to get a crystal clear pool?

 

[mknauss]

I would suggest doing a Overnight Chlorine Loss Test tonight or tomorrow night to check for FC loss overnight.

 

[Richard320]

7 FC is not really that high for 20 CYA. SLAM level for that is 10 FC. And of the CYA is closer to 30, you'd want FC up to 12.
There's this SLAM Process

And the movie

 

[Allykeep]

I would suggest doing a Overnight Chlorine Loss Test tonight or tomorrow night to check for FC loss overnight.

I completed the OCLT tonight and already see a change (increase) in FC and CC. Will recheck in the morning like advised but am thinking a SLAM is in my future. Looking at the Chlorine/CYA chart, do I need to increase my CYA to 70 then increase FC while lowering the pH? I’m trying to figure out how much we need of all supplies for a store run.

 

[mknauss]

Your CYA should be at least 30 ppm but do not go higher than that if you need to add CYA. Your pool is treated as a non-SWCG pool during SLAM. You will be using liquid chlorine, not the SWCG.

pH should be lowered to 7.2 - 7.5 before you start SLAM.

 

[Allykeep]

I would suggest doing a Overnight Chlorine Loss Test tonight or tomorrow night to check for FC loss overnight.

OCLT last night at dark FC 9.5. CC 1, this morning FC 7, CC 1. Starting SLAM today.

 

[Allykeep]

Update: Have been SLAM-ing for a week now. Test, brush, test, repeat. Pump is running 24/7. CYA remained at 30 throughout the week. Very challenging to keep pH at 7.2. Even after pounds of dry acid added, pH liked to sit at 7.5. FC runs anywhere from 18-22. CC is now at zero. The pool is pretty clear with the exception of a fine sediment layer on steps. Even when stirred up, it doesn’t cause the pool to get cloudy. This morning’s results are:
CYA 30
FC 21.5
CC Zero
pH 7.5
Plan to test OCLT tonight to see if all SLAM criteria has been met. Any advice or guidance at this point? If all criteria is met, how do I get rid of the sediment?

 

[mknauss]

Your pH test is invalid when your FC is above 10 ppm. Do not bother testing anything but FC during the SLAM.

Your FC is very high -- your SLAM level FC is 12 ppm. No need to go higher than that. Long periods of FC above SLAM level can damage pool surfaces and equipment.

No need to do a OCLT until you have a crystal clear pool. You do not if you have sediment in the pool.

 

[mknauss]

Test your TA. I am concerned about the 'pounds' of dry acid. You should also not be using dry acid. The sulfates in it can destroy your plaster and SWCG.

 

[Richard320]

Update: Have been SLAM-ing for a week now. Test, brush, test, repeat. Pump is running 24/7. CYA remained at 30 throughout the week. Very challenging to keep pH at 7.2. Even after pounds of dry acid added, pH liked to sit at 7.5. FC runs anywhere from 18-22. CC is now at zero. The pool is pretty clear with the exception of a fine sediment layer on steps. Even when stirred up, it doesn’t cause the pool to get cloudy. This morning’s results are:
CYA 30
FC 21.5
CC Zero
pH 7.5
Plan to test OCLT tonight to see if all SLAM criteria has been met. Any advice or guidance at this point? If all criteria is met, how do I get rid of the sediment?

Vacuum the dust up.

And you shouldn't have been messing with the pH. Above 10 FC the pH test can't be trusted. It even says as much in SLAM Process under prerequisites.

Check and adjust the PH to between 7.2 and 7.5. The PH test isn’t reliable during SLAMing so make sure to take care of this before you start.

 

[Allykeep]

Test your TA. I am concerned about the 'pounds' of dry acid. You should also not be using dry acid. The sulfates in it can destroy your plaster and SWCG.

TA is 140. The dry acid used was Clorox’s pH Down and/or 20 Baume Muriatic Acid. I opted for what we had available or had access to and honestly didn’t know the issues it could cause. During the SLAM process, we never added chlorine due to the increased levels of FC. The pool chlorinator was set to 75%. Please advise what to do. I’ve seen how helpful you e been to others and appreciate your help greatly. I can do nursing but getting this pool to the perfect balance has been quite challenging. As far as vacuuming goes, I have been. We have a Polaris running 8+ hrs a day and I have gotten in the pool with a ShopVac to get the extra sediment up. We tried to use a vacuum that attaches to the skimmer with no such luck. So guidance is appreciated as pools are not my skill set but I’m trying.

 

[Richard320]

Pool vacuums are pretty simple. Unless you have more than one skimmer or you have the main drain connected to the skimmer and are using a vacuum plate. Then it requires some improvisation.

What was the problem? Not enough suction, or it started sucking air and the [ump lost prime. or what? We can get that figured out and then you'll be able to vacuum up microscopic stuff and strain it out.

As an aside, the 140 TA is good -- that means you didn't overdose the acid. Or if you did, it will rebound fast. So that's good news.

You can see the floor. You're already ahead of about half the pools in America. And yours will continue to improve, whereas they'll be lucky to make it to August without it going green at least once.

 

[mknauss]

we never added chlorine due to the increased levels of FC.

The SWCG was adding chlorine. You are still way above SLAM level FC.

 

[Allykeep]

Pool vacuums are pretty simple. Unless you have more than one skimmer or you have the main drain connected to the skimmer and are using a vacuum plate. Then it requires some improvisation.

What was the problem? Not enough suction, or it started sucking air and the [ump lost prime. or what? We can get that figured out and then you'll be able to vacuum up microscopic stuff and strain it out.

As an aside, the 140 TA is good -- that means you didn't overdose the acid. Or if you did, it will rebound fast. So that's good news.

You can see the floor. You're already ahead of about half the pools in America. And yours will continue to improve, whereas they'll be lucky to make it to August without it going green at least once.

Thanks for the encouragement! The vacuum attachment we used suctioned to the skimmer however, it did not suction at the vacuum end. We primed the hose by completely submerging it in the pool to fill the line. The pool has 2 skimmers and a filter drain in the deep end. I don’t know if the drain is attached to the skimmer. We didn’t install the pool just acquired it with the purchase of the home. The ShopVac method works, just time consuming and wastes a lot of water.
On another note, how should I lower the FC to 12, my recommended SLAM amount? Should I turn the SWG chlorinator % off?

 

[mknauss]

On another note, how should I lower the FC to 12, my recommended SLAM amount? Should I turn the SWG chlorinator % off?

Correct. Turn it off and test after 6 hours or so. You really should be using liquid chlorine while following the SLAM Process

 

[Richard320]

Lowering FC is just that easy. Shut off the SWG and let sunlight do the rest.

For the vacuum, you need to figure out the plumbing. Coming out the front end of the pump there may be valves. Experiment with them and see what stops when you shut it off. Then go look under the skimmer baskets. You may have more than one opening and you may have a diverter. It looks like a flying saucer. If you can post a picture, even better. We'll get it figured out. Full pump suction can be really strong. I can stick my vacuum to the floor of the pool to where I can budge it without fear of bending the pole, and pulling the hose out with pump on requires some muscle.

 

[Allykeep]

Correct. Turn it off and test after 6 hours or so. You really should be using liquid chlorine while following the SLAM Process

Ok, absolutely will do.

 

[Allykeep]

Lowering FC is just that easy. Shut off the SWG and let sunlight do the rest.

For the vacuum, you need to figure out the plumbing. Coming out the front end of the pump there may be valves. Experiment with them and see what stops when you shut it off. Then go look under the skimmer baskets. You may have more than one opening and you may have a diverter. It looks like a flying saucer. If you can post a picture, even better. We'll get it figured out. Full pump suction can be really strong. I can stick my vacuum to the floor of the pool to where I can budge it without fear of bending the pole, and pulling the hose out with pump on requires some muscle.

Pics of the pump and skimmer. We borrowed my brother in law’s vacuum attachment but would like to get our own if we can get the setup figured out. What do you recommend getting?

 

[Flying Tivo]

Take a picture of you equipment pad and post it. We can help.

 

[Flying Tivo]

Ok, turn the handle on the left so you put the OFF tab to one side of the suction. Check on your skimmer, if it still pulling water then label the pipe oposite to the OFF tab as skimmer and the other would be the main drain. As for the right side valve you can leave it as be. You need to vacuum with the skimmer only.