SWCG advice

[Razorhog]

Got a complete set of test results, including salt. Anyone care to take a look and see what I need to do? I guess the next step is adding salt?
FC - 6
CC - 0
pH - 7.4
TA - 80
CH - 60
CYA - 60
Salt - 800
Temp - 78F

 

[Rancho Cost-a-Lotta]

Use Pool Math to calculate the amount of salt needed to get you into range (3000-4000 ppm). Maybe target 3500 ppm for a +/- 500 buffer? I get 395 lbs, so nearly 10 40 lb. bags. Looks like you got some electrical and plumbing to do first.

Do you have a timer set up for SWG?

 

[Razorhog]

Use Pool Math to calculate the amount of salt needed to get you into range (3000-4000 ppm). Maybe target 3500 ppm for a +/- 500 buffer? I get 395 lbs, so nearly 10 40 lb. bags. Looks like you got some electrical and plumbing to do first.

Yeah I calculate 395 lbs to get to 3500 as well. The manual states ideal level is 3500ppm and to keep between 3000 and 4000. Guess I'll go ahead and get salt, install the SWG but not turn it on til after the salt is dissolved. I'll probably add like 8 bags and test tomorrow so I don't overshoot 3500.

 

[Rancho Cost-a-Lotta]

Good idea. Allow the salt to circulate for 24 hours before turning on the SWG.

 

[Razorhog]

Quick question for the chemistry gurus - I have a bucket of pucks and a bucket of cal-hypo. I'm definitely returning the pucks, but can cal-hypo be used with a SWCG?

 

[Rancho Cost-a-Lotta]

I'm not a chemistry guru, but I can answer that one. Cal-hypo contains calcium. Since you have a fiberglass pool and low CH, no harm, no foul. If I'm wrong, one of the chemistry gurus will kick me in the butt.

 

[ajw22]

You don’t want too much calcium in a fiberglass pool. Fiberglass pools can develop scale. If you add calcium then you need to watch the CSI to prevent scale.

It is better to not have calcium in your water. I would dispose the cal-hypo and not use it.

 

[Richard320]

Quick question for the chemistry gurus - I have a bucket of pucks and a bucket of cal-hypo. I'm definitely returning the pucks, but can cal-hypo be used with a SWCG?

In your case, yes, but only because you only have 60 CH. It looks like 25 lbs of 73% will only add 87 CH to your pool, which would still have your CH enviably low, and I doubt you'll need very much before the SWG is online.

You don't need CH, but it might prevent surface foaming.

 

[setsailsoon]

Yeah I calculate 395 lbs to get to 3500 as well. The manual states ideal level is 3500ppm and to keep between 3000 and 4000. Guess I'll go ahead and get salt, install the SWG but not turn it on til after the salt is dissolved. I'll probably add like 8 bags and test tomorrow so I don't overshoot 3500.

Razor,
What you describe is the way most people do it. In my case I added about half of the salt before I installed the unit. Wife has sensitive skin so I wanted to be sure she liked it before I opened the box...just in case! She loved it! Won't ever let me go back-good thing I like it too!

Chris

 

[Razorhog]

In your case, yes, but only because you only have 60 CH. It looks like 25 lbs of 73% will only add 87 CH to your pool, which would still have your CH enviably low, and I doubt you'll need very much before the SWG is online.

You don't need CH, but it might prevent surface foaming.

Excellent advice as usual, Richard. Thank you.

 

[Razorhog]

Installed, w00t

 

[Rancho Cost-a-Lotta]

Good Job!

 

[setsailsoon]

Installed, w00t

View attachment 100270

Nice work!

 

[Richard320]

I'll bet that's a load off your mind.

 

[Razorhog]

I'll bet that's a load off your mind.

Indeed it is. Night before last I had dreams about PVC

 

[Razorhog]

Salt is at 3800, just started up the SWG for the first time. Now to figure out output percentage and pump run times. Starting off with 25% at 8 hours.

 

[Rancho Cost-a-Lotta]

If I understand the conversion process correctly, on the Pool Math page you can use the "chlorine gas" drop down in the "Effects of adding chemicals" box to calculate FC increase. Your SWG produces 2.3 lbs per day (36.8 oz). At 100% and 24 hours, that's an increase of 16 ppm. Convert that down to 8 hours at 25% and you end up with an increase of 1.3 ppm per day. If you know your daily FC loss, you can set the SWG based on that.

 

[Razorhog]

If I understand the conversion process correctly, on the Pool Math page you can use the "chlorine gas" drop down in the "Effects of adding chemicals" box to calculate FC increase. Your SWG produces 2.3 lbs per day (36.8 oz). At 100% and 24 hours, that's an increase of 16 ppm. Convert that down to 8 hours at 25% and you end up with an increase of 1.3 ppm per day. If you know your daily FC loss, you can set the SWG based on that.

Very cool, thanks. Not sure of my daily loss yet as I've typically never had a CYA level this high. In the past it has been 3-4 ppm each day with CYA at 30-40. Lately I've been losing about 2-3 during daylight hours. OCLT last night was .5. Hmmm. 8 hours at 25% for 1.3 ppm won't be enough. 8 hours at 50% should be 2.6ppm which might be just about right.

 

[Rancho Cost-a-Lotta]

 

[Razorhog]

Sooo, another question. Right now FC is 8. Should I turn off the SWG until it comes down to 4? CYA is 60.