Pressure to returns just won't improve

[aquiapools]

There isn't much that I have not tried to improve flow through the returns in this pool, so I am "going to the mattresses" sort of speak. I hope to get some more ideas on this forum. It's an inground gunite 17500 pool with a 500 gallon integrated spa. The pool has 3 returns and the spa has 6. The return to the spa is simply pathetic. The return to the pool is OK, but still not nearly as good other pools I service with the same equipment.

Here is the equipment:
Pentair SuperFlo 1.5 HP pump with original motor
Pentair Tagleus TA60D sand filter
Spa blower (unknown brand)
Polaris PB40 booster pump
Hayward heater
Pentair Rainbow 320 chlorinator
All plumbed to 1-1/2 PVC
Normal clean PSI: 18

Here is what I have done so far:
1. Replaced impeller, mechanical seal and o-rings to main pump. Diffuser OK.
2. Reduced return eyelet sizes in spa and pool
*This really helped, but still isn't enough
3. Cleaned skimmer suction line with compressed gas
4. Backwashed filter when necessary (clean and current PSI: 18)
5. No debris in Jandy valves at equipment

Filter multiport settings from Filter to Bypass does not improve return pressure.

NOTE: There is a noticable change in water level each week of about 2 to 3 inches. We are aware there has to be a leak, but it has not been addressed. The leak has to be in a line or from the . I think if all other potential issues are ruled out, this may be our culprit.

Is there a way to test a motor to determine if it is OK or failing? I don't have a flow meter installed (should be standard on all pools) so I can't tell you what the turnover rate is.

Lets see what you got.

 

[JohnT]

I really doubt the motor is the issue. Motors will provide the power required to crank the impeller until they fail. If it isn't squalling from a failed bearing or smoking form an overload, you can pretty well count on it being good.

Without knowing how the plumbing is routed, it would be hard to understand the balance of flow, but I think it would be expecting a lot to have strong flow from even 6 returns at once, much less 9.

 

[Bama Rambler]

Which model Whisperflo is it, the WF-6 or the WF-26?
Can you post a pic of the equipment?
What model heater is it?
Can you bypass the heater?
What does the filter pressure run when in spa mode and in pool mode?
Are there any standard ball valves in the system?

 

[aquiapools]

**CORRECTION**

The pump is a SuperFlo, not a WhisperFlo. I edited my original post.

 

[aquiapools]

Which model Whisperflo is it, the WF-6 or the WF-26?
Can you post a pic of the equipment?
What model heater is it?
Can you bypass the heater?
What does the filter pressure run when in spa mode and in pool mode?
Are there any standard ball valves in the system?

Pic posted
The heater is a Hayward H Series 250BTU.
I can't bypass it unless I re-plumbed it.
I will have to revisit the pool to get specific PSI numbers for the different configurations.
There is a 3 port Jandy valve at the suction side, but a Pentair Ortega 3-port valve at the return side. The only ball valve on the system is on the booster pump supply side.

 

[JohnT]

Jason, did you get the PM I sent you?

 

[Bama Rambler]

With that pump at that plumbing head you're not getting but about 50 gpm flow through the system. Thats not nearly enough for 6 spa jets.

 

[aquiapools]

With that pump at that plumbing head you're not getting but about 50 gpm flow through the system. Thats not nearly enough for 6 spa jets.

In other words, the 1-1/2 pipe isn't going to carry the volume that I need for this system? Can I put a 2HP motor on this pump to compensate? I guess I could also close off some spa jets.

 

[Bama Rambler]

If you change the motor and the impeller it will help, but I don't know that it will make a great deal of increase. You cantry PMing Mark (mas985) and see if he'll take a look at it for you. He knows volumes more about hydraulics than I do.