waterfall re-plumbing

[TopJimmy]

I am re-plumbing my waterfalls to increase flow. The waterfalls are 3 each, 24" (Jandy). The first drawing is what I presently will have when I will bypass the filter, heater, SCG, and check valve. The second drawing is an alternative in addition to the bypass.
Question I have is: is the 2nd drawing worth the additional expense, ie how much more flow would I realize, if any, relatively speaking?

 

[ajw22]

How much GPM do you expect to get to each 24" waterfall?

What flow rate are you expecting out of the pump?

How much cost difference is there to do all the 3" pipe? Your limiting factor will be the 2" pump output and pipe before it splits into 3".

You want to keep the water velocity below 6 ft/sec on the suction and below 8 ft/sec on the pressure side of the pump.

Pipe Size	6 ft/sec	8 ft/sec
1.5"	38 GPM	51 GPM
2"	63 GPM	84 GPM
2.5	90 GPM	119 GPM
3.0"	138 GPM	184 GPM
4.0"	235 GPM	312 GPM

 

[TopJimmy]

My objective is to get as much flow as possible (while considering the cost/benefit of redoing certain junctions). My pool builder didn't do things right, then went bankrupt. I had to cap off 1 of the 3 waterfalls to increase pressure to the other two. I am hoping to re-open the 3rd waterfall, but the suction and pressure side piping needs to be modified. I know my main restriction to the waterfall is the filter, heater, check valve, and SCG. That's where I'll make the most difference--by bypassing these items.
Right now, with 2 waterfalls and no bypass, the water is reaching the pool acceptably.
But to throw out a number, I'd think at least 120 GPM, maybe 140 GPM. The Jandy sheer manual shows the max projection at 20 GPM per ft. I have 6 ft of sheers, so that is 120 GPM minimum required (my waterline is 2 ft from the sheer). I'd like to get that to more like 2.5 ft, though, so that's the reason for 140 GPM.
Cost difference is probably $500, but there's also the effort required for me to dig up the pipes near the equipment pad, then ream out the 3" to 2" bushings, etc.
If this is too complex to figure out the cost/benefit, maybe just go ahead and do it, knowing that I've done all I can?

 

[ajw22]

If this is too complex to figure out the cost/benefit, maybe just go ahead and do it, knowing that I've done all I can?

Going through all the effort and expense you might as well give it the max you can with all 3".

 

[Jimrahbe]

Jim,

The IntelliFlo is not a waterfall pump and I suspect that you are not going to see much difference, but I have been wrong many times before...

Let's see if we can get these two guys to chime in... @mas985 @JamesW

Just a side note to show how people are different... I never run my waterfall wall any more and wish I had not spent the extra money on it. It works fine, it is just me.. When the waterfall looks good, the noise is obnoxious, and when the noise is bearable, the waterfall looks bad... Sigh!

Thanks,

Jim R.

 

[JamesW]

The suction is going to be the limiting factor.

What is the suction to the pump?

 

[TopJimmy]

Suction currently is two 3" main drains and one 2" skimmer going into 2" manifold then a 2" diverter valve prior to the pump.

What I will change it to:
When waterfall is called for: valve actuator causes suction to come from two 3" mains feeding a 3" manifold with a Pentair FullFloXF 3"-2.5" diverter valve then going to 2" prior to the pump.

sidenote re the waterfall in general: I agree it's completely useless and not worth it. However, the wife really wants it so what can I do.

 

[mas985]

Suction currently is two 3" main drains and one 2" skimmer going into 2" manifold then a 2" diverter valve prior to the pump.

Normally MDs are tied together and only one line is sent back to the pump. Is that how yours are plumbed?

It would have been helpful to have the drawing include the suction side as well.

But having a single MD line with multiple return lines could possibly send the the pump into cavitation. There should be more head loss in the return than the suction. Will you be running the skimmer at the same time? You probably should not if you are bypassing the filter. That could send debris into the sheer descents. Those normally require filtering to prevent clogging.

With one 60' 3" suction and one 60' 3" return line feeding 3 2" waterfalls and with 2" on pad, the estimated flow is around 157 GPM which is getting close to pump runout.

One solution is not to bypass the filter assuming you have a large one that can support 120+ GPM. This would drop the flow rate to 138 GPM plus filter the water so the sheer descents are protected.

BTW, I wasn't quite sure which Intelliflo you actually had so I assumed the 011056 for the above estimates.

 

[TopJimmy]

I looked again at the pre-construction photos and you are right: I have only one 3" main drain pipe at the pad.
When I have the waterfalls running I will be on main drains only (skimmer off).
Pump is a 011056. I attached a drawing of what is and what I am thinking of doing.

 

[mas985]

You are planning to add a second skimmer?

What does the return plumbing look like right now (i.e. what size plumbing is going to the waterfalls and how many lines)?

Can you post a picture of the pad equipment and plumbing?

 

[TopJimmy]

Post #1 of this thread is the present return and return plan. Pool builder only hooked up one of the skimmer lines, so I thought hooking up the other one might be a good idea (1 skimmer, but 2 pipes).

 

[mas985]

I think the only issue you really have is the heater. Bypass that, and you should get more than enough flow rate.

 

[TopJimmy]

Ok I’ll check it out and see what happens. I was going to put in a heater bypass w intellivalve also, so might as well do that first.

 

[Jimrahbe]

so I thought hooking up the other one might be a good idea (1 skimmer, but 2 pipes).

Jim,

Just to be clear... You have two skimmers and one is just not connected, or you have one skimmer that has two pipes???

Two different pipes from one skimmer would be very odd...

Which is it??

Thanks,

Jim R.

 

[TopJimmy]

1 skimmer with 2 pipes. The second pipe is plugged at the skimmer, currently. I think it’s supposed to be connected to the main drain but it’s not. The other end is capped at the pad.

 

[TopJimmy]

Pretty much all done. Took all winter. One more intellivalve to place on skimmer pipe (to make vacuuming a feature group) and need to paint the pipes, then fill in with pea gravel. Also added acid injection, ORP, nodeJS-PC. Flow cells and Raspi in my basement. Still working on getting ORP automation set up. The all-black pipe pic is “before”

 

[TopJimmy]

Finally got around to painting, zip-tying, labeling, and putting pea gravel back in.