Can't hold TC or FC with a SWG?

[prettyblues80]

Hi All,

My first post here! I am a new AGP owner (22x52 Intex XTR). I am struggling to keep my chlorine levels up, and my alkalinity is high despite my pH being 7.5. I am not sure if I should just add a lb or two of non-chlorine shock and run the generator on boost, or if I need to SLAM with chlorine? Here are my current levels tested with a 6-way test kit from Leslie's.

TC = 1
FC= 0.5
CC = 0.5
CYA = 45
pH = 7.5
Alk = 210

10,500 gallon pool. Water is clear, just can't hold on to chlorine even with the solar cover on, and it has been 75-80 degrees the last few days. Thoughts?

 

[JimMarshall]

What SWG do you have?
Follow the SLAM Process

Your CYA is low for a SWG.FC/CYA Levels
Additional reading-ABCs of Pool Water Chemistry

please fill out your signature with your pool size and equipment

 

[mknauss]

Welcome to the forum!
What SWCG do you have? How long are you running it and at what % generation? Can you fill out your signature for us?
Do not add non-chlorine shock. It will mess up your chemistry readings. Use liquid chlorine (bleach).
I suggest you read ABC's of Pool Water Chemistry.

 

[prettyblues80]

I have the Intex SWG Model ECO6110. It doesn't have the option to change the percentage of generation, just the number of hours it runs, and has a "boost" mode which essentially just lengthens the amount of time the generator runs.

 

[mknauss]

That SWCG can generate 0.62 lbs of chlorine gas per 24 hours. That is 7.2 ppm FC per 24 hours in your pool.
So you will need to run that 12-16 hours per day to generate the FC you need each day.

Add enough liquid chlorine to raise your FC to 5 ppm. Then run the pump/SWCG for 16 hours. Test FC the next day and see if it goes up or down. Adjust the run time as necessary.

 

[Msch99]

Assume your CYA is 50, not 45. Any time you are between lines, use the highest CYA.
Your TA will slowly come down as you add Muriatic Acid to lower PH.
Welcome to the forum and Good Luck on your mission!

 

[prettyblues80]

Ok, so I added 6 cups of 10% bleach (liquid Chlorine) and it brought my FC up to 5-6, my CYA was more like 55 than 45, but seems to still be on the low side. I backwashed my filter and will run my pump overnight and the auto vacuum and retest in the morning. I will also run my SWG for 12 hours tomorrow. Does this seem reasonable?

 

[mknauss]

Sure. I think 12 hours will not be enough in Paso Robles. But you can give it a try.

 

[mknauss]

Also. Your test kit is only good to 5 ppm TC, right? You really should get a FAS-DPD test kit in the very near future.

 

[wireform]

Ok, so I added 6 cups of 10% bleach (liquid Chlorine) and it brought my FC up to 5-6, my CYA was more like 55 than 45, but seems to still be on the low side. I backwashed my filter and will run my pump overnight and the auto vacuum and retest in the morning. I will also run my SWG for 12 hours tomorrow. Does this seem reasonable?

Since it's night time we can be sure the uv isn't consuming your chlorine. Check in 30 minutes or there about to see where the chlorine is holding. If it's disappearing you then know you have algae at the beginning stage and you'd need to slam.

 

[prettyblues80]

The kit I have has a range of 5-10ppm. I have this one: Taylor Test Kit

 

[mknauss]

OK == so you are using a 10 ml sample of pool water, adding one heaping scoop of R0870 powder, and adding drops of R0871 reagent until the sample turns clear. Each drop is 0.5 ppm FC.

That is great.

 

[prettyblues80]

@wireform it seems to be holding at 5ppm, and I put the chlorine in about 1.5 hours ago. I am still a bit confused on what I should do to SLAM my pool. Do I really need to get my PPM to like 24 and then let it come down to normal limits on its own without running the SWG?

 

[mknauss]

What does your water look like? You had not mentioned any issues.
Might be best to do a Overnight Chlorine Loss Test tonight. That means leaving your SWCG off over night.

 

[prettyblues80]

@mknauss now that I look at what you sent, that isn't what I have. I have this one: TEST KIT. Doesn't have the powder you mention. Ugh! I didn't get the right test kit?

 

[prettyblues80]

@mknauss yes I planned on leaving the SWG off overnight and testing again in the morning to see how much FC I lose. The water has been fine, totally clear, but I did put the cover on it a few days ago (Sunday) and there seems to be more sediment at the bottom of the pool than I thought would be there when we covered it? So maybe there is some algae?

 

[mknauss]

No. Parts of it will work. But you need the FAS-DPD. The rest is OK for now, but a full proper test kit like a TF100 will be best to get when this kit needs refills.

Good idea on the test overnight. You get some dust there. So hopefully that is it.

Realize you cannot SLAM with that test for FC. And your OCLT is compromised as well.

 

[prettyblues80]

I have also noticed a little green tinge to the skimmer sock, so there's that.

 

[prettyblues80]

Ugh, Crud. So, I need to get that test kit and we are probably screwed out of swimming this weekend?

 

[mknauss]

It would be good to get the kit but swimming is OK as long as you keep chlorine in the water. Algae is not dangerous, it is too low of chlorine for your CYA that is. With your kit, you can keep 5 ppm FC in the water and that kills all the pathogens that are an issue.

As long as the water stays clear enough to see the bottom.