We are in mid construction of our pool and our contractor is little help because he's never done multiple sheer descents. 2" line running to 3 SD's, 1-36" and 2-24". We plumbed a loop at the bottom and ran three tees in the loop with vertical 2 inch pipes coming up to each sheer descent. I am going to run a separate pump album was thinking about getting the Intelliflo VS to match our other pump and then I saw Pentair has a waterfall pump. The 2 inch line runs about 50 to 60 feet from the pump pad to the waterfalls. Recommendations would be greatly appreciated. I'm also a little disappointed that our CMP natural wonders waterfalls come with 1-1/2" rock traps and 2" are not available. I hate to reduce down the size and then go back up to 2 inch but I guess I don't have much choice. I'm putting ball valves on each one of the vertical 2 inch pipes coming up to the sheer descent so I can fine-tune them.
Pump recommendations for multiple sheer descents
- Thread starter armypilot
- Start date
- Jun 22, 2014
- 49,303
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Welcome to TFP! 
Let's ask our water hydraulics expert @mas985 for some thoughts. Good luck on the build.
Let's ask our water hydraulics expert @mas985 for some thoughts. Good luck on the build.
- May 3, 2007
- 17,393
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Sheer descents usually require about 12 GPM/ft or 60 GPM total which is fine for 2" pipe. A waterfall pump such as the Pentair AF-120/180 would probably work but it depends on the plumbing layout.
You mentioned 60' runs but does the loop have it's own filter? It is usually a good idea to have a filter for sheer descents to prevent any blockages even with a rock trap. But even with a cartridge filter, the AF-120 should still work ok with an operating point of 71 GPM @ 21' of head. But I am assuming a good design with few valves and fittings. Your results may vary.
If you want a bit more dynamic action from the descents, I would go with the AF-180. It will give you a bit more headroom too. That operating point would be 76 GPM @ 24' of head.
You mentioned 60' runs but does the loop have it's own filter? It is usually a good idea to have a filter for sheer descents to prevent any blockages even with a rock trap. But even with a cartridge filter, the AF-120 should still work ok with an operating point of 71 GPM @ 21' of head. But I am assuming a good design with few valves and fittings. Your results may vary.
If you want a bit more dynamic action from the descents, I would go with the AF-180. It will give you a bit more headroom too. That operating point would be 76 GPM @ 24' of head.
They (CMP) are recommending 1 gpm per inch. I have 84" so I need 84 gallons per minute. I am also using the Pentair East Touch automation system and want to hook the waterfall pump to the automation so I can turn on the waterfalls with my phone. I talked to Pentair and they recommended using another Intelliflo VSF since it is compatible with the automation. I am having a hard time trying to find a cartridge filter with a 2" in/out to use with the system. Thoughts?
- May 3, 2007
- 17,393
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Pretty much all cartridge filters have 2" in/out.
www.pentair.com
My mistake on the GPM. If you upsize the pipe to 2.5", then:
AF-120 should be able to deliver 88 GPM @ 18' of head.
AF-180 should be able to deliver 97 GPM @ 22' of head.
The limiting factor is really the pipe size.
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My mistake on the GPM. If you upsize the pipe to 2.5", then:
AF-120 should be able to deliver 88 GPM @ 18' of head.
AF-180 should be able to deliver 97 GPM @ 22' of head.
The limiting factor is really the pipe size.