Looking for pump HP recommendations on a 60’s era pool with 20 returns!

[TomR]

Hey guys! I’m new to the forums and a new pool owner. I bought a 1964 ranch just outside of Atlanta GA and did a 6 month renovation. The house is practically new but the pool is another story. It was built around 1965 by Artistic Pools in Atlanta... a reputable builder still in business. The pool is gunite 40x20 rectangular and approximately 35,000 gallons. The neighbors tell me it was built as a heated pool and has 20 return fittings - 6 in the pool floor and 14 around the perimeter. The heater was removed years ago and the pump and filter have been replaced over the years but could use an overhaul. The pool has 2 skimmers and one main drain. I believe the pool is called a flooded system... the pump house is behind the pool about 6 feet below the pool level. I went to Artistic Pools to see if they still had a blueprint to get an idea of how the pool is plumbed but they couldn’t locate anything in their archives. The pool appears to have been plumbed with 2” schedule 80 PVC... it’s grey in color. At the pump house I have one 2” line coming from the main drain and one 2” line from the 2 skimmers which are tied together somewhere underground. There is one 2” line returning to the pool. All of the 20 returns appear to be plumbed with 1” schedule 80 PVC and they have 3/4” fittings on them. The fittings originally had some type of screw on restrictor but at this point none have a restrictor. The opening on the 20 returns is 3/4” and the inside diameter of the piping to the returns appears to be 3/4” or slightly larger so I’m not certain of the true pipe size for the returns. I don’t know if the plumbing under the pool for returns is 2” with 1” branches tied to the returns or the entire plumbing for the returns is 1”!? I am doing a DYI reno on the pool and it currently remains crystal clear with no issues balancing the chemicals. The only issue I have is that there is zero water movement when the pump is running so I get a lot of surface debris which stays stagnant and doesn’t move towards the skimmers. I have inserted 3/4” winter plugs into the returns and have confirmed all are working. If I close all but 2 of them I get pretty decent flow out of the 2. I am planning on replacing all 20 fittings with eyeball fittings which can be closed or opened. The current old pump is a Flotec 1 HP and the current old filter is a Pentair Nautilus FNS 36 DE. I estimate between 50 and 60 feet of head but am worried about increasing the pump HP since the return plumbing seems so small although there may not be as much resistance since there are 20 returns?! I was looking at the Pentair 011018 VSP 3 HP pump with the thought that I could get it set up and turn down the RPM to get just the right flow. Anyone out here run into this type of setup from the 60’s who might provide some advice from personal experience?

 

[chiefwej]

I don’t have any experience with a similar pool, but I’m very familiar with the Intelliflo 011018 3hp VS pump. The beauty of a VS pump is you can tailor the speed and flow to suit any need. I have an infloor cleaning system with six zones, and a total of 25 cleaning heads, a SWG, a solar system. I can program my pump’s speed and timing to the precise need for cleaning, solar heating, chlorine production, or set it to a very low (economical) speed for extra filtration. It is the most used and recommend among pool owners on this forum. Since the VS pump is infinitely adjustable, you really can’t oversize it.

 

[Jimrahbe]

Tom,

Welcome to TFP... a great place to find the answers to all of your "Oldies but Goodies" pool questions...

I think just adding eyeballs will make a big difference in your skimming. You need to get the eyeballs where you can rotate the "eye" so that you can control the direction of the water's flow. Skimmers work best if you can get the pool water to slowly rotate like a toilet being flushed..

The IntelliFlo 011018 will work great for you.

Make sure you use pump unions to install it. Much easier to install and prevents the leaks that you often see at the threaded input and output connections on the pump. Pump unions have an O-Ring that prevents these types of leaks. See this link for what they look like... https://www.google.com/aclk?sa=L&ai=DChcSEwimqMXkjojdAhXEusAKHd-ADAgYABAaGgJpbQ&sig=AOD64_3tGkGuZwVUzovoAimpWvrOnAIxxQ&ctype=5&rct=j&q=&ved=0ahUKEwi-ysDkjojdAhVM7qwKHbjbCycQ9aACCL4B&adurl=

Thanks,

Jim R.

 

[TomR]

chiefwej and Jim - I really appreciate your input! It looks like the 011018 is the way I am going to go!