SWG not used in years. How to tell if it still works?

Plefasu

Bronze Supporter
Aug 28, 2020
19
Phoenix
I have a 20,000 gallon pebble pool with a 4 cartridge filter. Moved in 4 years ago and the previous owners used chlorine so I continued with that. I noticed the system has an SWG but I've never used it. Any tips on how I can tell if it works? I was thinking about isolating the hot tub and running the salt setup on it to see if it will generate.
IMG_20200914_135134.jpg
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,617
Laughlin, NV
Welcome to the forum!
You will need to add salt and be sure the content is up to the level needed by the unit. You can do that by isolating it to the spa and adding enough salt just for it.
SWCG is the easiest method of chlorinating a pool. I suspect the owners used a pool service. They make less money if you are not buying chemicals from them.
I suggest you read ABC's of Pool Water Chemistry.
 
  • Like
Reactions: Mdragger88

Newdude

Well-known member
Jun 16, 2019
4,441
NY
Hey plefasu and Welcome !! If you get power to the control panel (could be unplugged or have a breaker off), you’ll know if it fires up at least. Then go about testing the spa like Marty said above.

We are moving and 2 of the houses we looked at had old SWGs that the previous owners didn’t want to replace when it was time. They both switched back to chlorine and left everything in place instead of paying someone to come remove it all. It could go either way.
 

Plefasu

Bronze Supporter
Aug 28, 2020
19
Phoenix
Thanks for the quick replies. I have scoured this website for literally hours as I was having high CYA issues and some delaminated pebble so the pool was drained and I repaired the pebble and am now conforming the BBB method. Now that that is all working very well(pool is more sparkly than ever) I thought I would look into the SWG. The unit is powered and lights up when I turn it on. If I dump the required salt in the hot tub and it doesn't work does having the residual salt negatively affect things at all? The hot tub is only like 900 gallons so I would think not?
 

Newdude

Well-known member
Jun 16, 2019
4,441
NY
The unit is powered and lights up when I turn it on
Then it will either produce chlorine or not if the salt level is correct. One step out of the way. If you add salt and it doesn’t work, it doesn’t harm anything. Many people add salt without the SWG just for the feel of it.
 
Last edited:

Plefasu

Bronze Supporter
Aug 28, 2020
19
Phoenix
Thanks for the link. Mine is the A5 which at $439 not sure if it would be worth replacing if it doesn't work. Should I clean my existing one before testing it out? I cant see calcium, it has a blue tinge on the fins though.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,617
Laughlin, NV
Blue tinge is probably copper. I suspect copper algaecide has been used. Do you have any staining?
No reason to clean if no calcium
If you wish to convert to SWCG regardless, which I recommend, we can discuss that.
 

Plefasu

Bronze Supporter
Aug 28, 2020
19
Phoenix
I don't have any staining and I haven't used any algaecide but it may have been the previous owner. I would like to use the SWG but want to make sure its working. If I use the hot tub method to test how long will it be before I know if its working properly? I ask because the pool and hot tub run on the same filter so I will have to isolate the hot tub and the pool will not have circulation during my test. I just got my pool balanced and was thinking if I bring the pool to SLAM levels it would be fine if the hot tub test only takes a couple days.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,617
Laughlin, NV
Sounds like a good plan. Brush or swim in the pool to mix it up during the test.
I would think if it works for a few hours and you see bubbles in the returns, it is working. But also plan for its replacement as the system is obsolete.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,617
Laughlin, NV
The control board can go bad as any electronic item can. Sitting in the desert sun does them no favors. If the cell needs replacement, you really have to consider if it would be better money spent going with a new system.

I see you have a VS pump. Do you have automation? Is there a standalone timer on the pad?
Different SWCG's would be advisable depending on the answers ----
 

Plefasu

Bronze Supporter
Aug 28, 2020
19
Phoenix
I have a Pentair intelliflo vsp that has a timer. That is the only automation. There is a timer in the electrical box but its the old school yellow wheel timer you set with screws. It is connected to the pump from when it was not vsp and is just always on since the pump has its own timer.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,617
Laughlin, NV
OK -- good to know. The SWCG needs to be wired through that old school timer. And the VS pump wiring needs to go on the Load side of the timer. The SWCG wiring on the Line side. That way the SWCG can be controlled by the timer. You then set the SWCG to operate within the time you have the VS pump set to run.
The SWCG should have a flow switch, but that is the Secondary safety device. The Primary safety device is removing the power from the SWCG when the pump is not running. A SWCG can explode if run without water running through it.
 

Plefasu

Bronze Supporter
Aug 28, 2020
19
Phoenix
Thanks for bringing that up. They are both wired on the line side of the timer as the old pump wasn't a VS so the swcg and the pump came on with the one timer. I'll rewire the pump to the load side. That will allow me to run swcg for the necessary time but still have the pump run longer if needed. I'll test out the swcg and if it's not working properly we can talk about new systems. Just got the premium membership on poolmath as this site has been a huge help!
 
  • Like
Reactions: mknauss

Plefasu

Bronze Supporter
Aug 28, 2020
19
Phoenix
I put 25lbs of salt in my hot tub that I estimate to be about 800 gallons. I turned on the swcg and made sure it was isolated to the hot tub and that water was flowing. I don't get any error lights on the resilience box but I cant get it to go over 20% with the dial. I then cleaned the cell and the barrel leads in 1/10 water/ muriatic acid for 20 minutes and rinsed and reinstalled. I am getting the same thing, wont go over 20%. Does this mean the cell is bad? I am going to check chlorine level in the hot tub in a couple hours to see if its increased but it doesn't seem to be fully functional. If its bad does it make more sense to buy a whole new system or buy a new cell?
 

Newdude

Well-known member
Jun 16, 2019
4,441
NY
If its bad does it make more sense to buy a whole new system or buy a new cell
That’s an age old debate with no clear answer. You can save half the cost of the full system this year and the power center can fail next month/year and you’ll have to replace that anyway because your cell has plenty of life left. Or it lasts another 4 years and it was wise to only buy the cell.
whattayagonnado.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,617
Laughlin, NV
Looking at your picture of the control box, you are seeing the 20% on the lights, correct? Have you turned the knob to full power? The screen shows if you are showing between 10% and 80% the cell needs cleaning (which you have done) or it is seeing low salt. You are right no the edge with the salt. So you might add 5 more lbs salt and let that circulate for a couple hours.