lbc1965

New member
Feb 26, 2025
4
Southern New Hampshire
Pool Size
24000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Have had a chlorine inground 20x40 Roman end 24000 gallon pool for many years and have decided to try the salt route. I am in New England so pool opens just before Memorial Day and closes just after Labor Day. When opening I typically dump 20 gallons of liquid shock, vacuum the next day and in 3 days the pool is crystal clear.
Couple of questions:
- should I follow same 20 gallons process and then turn on SWG when pool is balanced? Water will be murky green when cover is removed.
- plan on installing Pentair IntelliChlor 40 and using a Pentair Supleflo VST pump. Mount the IC40 vertical but do I need a bypass loop using this pump?
- what test equipment should I use….strips? Taylor liquid? Digital tester?
Thanks
L
 
Hey 65 and Welcome !!!


should I follow same 20 gallons process
No. We don't follow dump and pray here. We test and prove :)

With no algae present whatsoever:
Overnight Chlorine Loss Test
Its possible to not need anything at all, and when closed propely, likely that nothing is needed.

With algae present :
SLAM Process
what test equipment should I use
Test Kits Compared

Either TF test kit from tftestkits.net beats the equally priced Tayor equivalent. If you get the TF100 salt, add the smart stir thats included with the TFpro/salt.

Both standard kits come in salt versions for $20 more, including the $30 salt test, making them even better values.

Once balanced, test the salt baseline and add 75% of the remainder. Creep up to target allowing at least a full day to mix each addition of salt.
Mount the IC40 vertical
The ICs have internal flow switches and need to be mounted with 'upflow' so gravity doesn't close the switch when it fails. Hydrogen gas will build up when it happens with no flow and explosions are possible. So they get mounted 'up' or horizontal.

You also need a timer for the SWG so that it cant turn on with the pump off. Then the flow switch is a failsafe and not the primary safety measure.
but do I need a bypass loop using this pump?
No.
 
Thank you for your input! When I open the pool after 8 months covered/stagnant it is murky green….12” visibility that is why I dump so much chlorine. Is this wrong??
Pentair says to mount vertical. You mention upflow and to mount it “up” but then you say horizontal. Horizontal or vertical??
I run the pump 24/7 but most of the time at low rpm, just enough to keep the skimmers going. The pump is capable of 140 gpm so that is why I was looking at a bypass loop. I have not been able to get a direct answer to rpm vs bpm.
 
Pentair says to mount vertical. You mention upflow and to mount it “up” but then you say horizontal. Horizontal or vertical??
Either. But if vertical, it needs to go up, not down.
When I open the pool after 8 months covered/stagnant it is murky green
It needs a SLAM Process. (<--- click blue links)

Without confirmation tests you got it all, anything else is dump and pray. Algae is microscopic and by the time you see it, it's waaaaaaaay to late. If any remains which hasn't grown exponentially to the point of being seen, it can plague you all season.
The pump is capable of 140 gpm so that is why I was looking at a bypass loop
ICs are designed to work with all pool pumps.
 
If you open your pool a little earlier and close a little later, you likely won’t have to green swampy mess every year. The good rule of thumb. is to close it when the water temperature is below 60 and open it up when the temperature reaches 60. If you do that There’s a good chance you’ll have a very easy opening. 20 gallons of chlorine can do a lot of damage all at once.
 
  • Like
Reactions: Newdude
Ok ok, I will do it correctly and have water tested before I add anything and will probably have to SLAM.
Still confused on the bypass loop….pentair says I need one if over 80gpm which I will be when I vacuum. Can I just turn the SWG off while vacuuming? Do I need a diverter?? Am I way over thinking this??
 

Attachments

  • IMG_8056.png
    IMG_8056.png
    566.3 KB · Views: 7