What RPM do i need???

[interpim]

I have an older pool, that was put in sometime in the 70's... it has 1 skimmer and 1 bottom drain. There are 2 returns in the pool, but im not sure where it splits between the filter and the pool.
We installed a new pump and filter last year (Pentair clean and clear 420, and intelliflo vs pump.) We are considering converting to saltwater, but i understand it requires 25 gpm of flow to operate correctly. I typically leave my pump on 24 hours a day at low RPM, but im not sure i would get the gpm required. Is there a best guess on what rpm to run my pump at to maintain 25 gpm, also, if the rpm is fairly high, will running the pump on low speed for most of the day then doing a higher speed interval to create chlorine damage the SWG?

 

[Divin Dave]

I have the same pump you have with a Pentair IC40 SWG. I run my pump at about 1100 RPM to get enough flow for the SWG to work.

Your experience might be a little different depending on how much head loss you have in your plumbing. It probably wont be much though.

 

[Jimrahbe]

My Intelliflo will also satisfy the flow switch in the IC40 at 1,100 RPM. I run mine at 1,200, just to make sure. At that RPM it only draws 168 watts.. I have a slightly larger filter, but I doubt that will make any difference at all.

I believe that having a few inches of straight pipe before the SWG is important for keeping the flow switch happy at very low RPMs. You might want to keep that in mind when you install yours.

Jim R.

 

[GaryT58]

My pool is newer, 1 skimmer, 3 returns. My Autopilot Total Control (but would be same for any of their units) only requires about 15 GPM to operate. It will bypass any flow greater than 20 GPM away from cell. I am able to get down to about 600 RPM before the cell complaining about flow. So my lowest setting could be 650, but set to 800 just to make sure if sand filter starts to get dirty it won't restrict flow too much. I also like to run 24/7.

 

[interpim]

Thanks for all the replies, that was my biggest concern... i run mine at 950 rpm now unless im running my vac. So a couple hundred more wont hurt me to much.