Spa plumbing, return to filter through bottom or side drain?

[ctrlz]

I have an in-ground pool with attached spa which spills over to main pool. The spa has 2 bottom drain openings and 2 side drain openings located about 12" above spa bottom. Both side drain openings have curved grills to reduce entrapment risk. There is a single 2" return also located about 12" from bottom. Multiple spa jets are arranged at the typical level, maybe 36" from spa bottom. The spa has a separate jet pump.
As currently configured the jet pump circuit has suction connected to the bottom drain and returns to the waist-level jets. The main circulating pump draws from the SIDE drains and returns to the single 2" side outlet. I believe this is plumbed incorrectly, as the dirt and sand which settles to the bottom doesn't get drawn through the filter, as the only filter is on the main circuit. Also, when the jet pump is used it is blowing the dirt near the bottom right back at the bather. This is not necessarily noticeable, I just realize it must be happening!
So this all sounds wrong to me, and I am just wondering it there is any logical reason to keep things as they are before I replumb the thing!

 

[mas985]

Welcome to the forum!

If the suction lines are the same size (i.e. diameter), then you could swap them between the filter and jet pumps. Is that what you were planning?

However, if the side wall suction lines are smaller than the bottom drain, it could affect jet pump performance.

 

[ctrlz]

It's all 2". The other problem with this present setup is I can never drain the spa lower than that side drain.
Yes, I have been thinking about swapping them for the 10 years I have owned this pool! This is for a rental property in Florida I only visit a couple of times per year. Usually there are more important projects that command my attention, and prevent me from messing with the PVC. Before I switch them, I figured I'd see if there was any logical reason for them to be built this way. From my reading, it seems the builder SHOULD have just installed two floor drains.

 

[mas985]

Mine is plumbed with a single set of MDs but separate suction lines, one for the filter and one for the jet pump so it can be done that way. I am not sure why they did it that way.

But how many spa jets do you have? 2" is very small for a spa. Are the jets effective?

 

[ctrlz]

Not sure, but probably 7-8 jets. The jet pump is 2.5 HP. They are plenty effective for me. I would consider going to a 2 HP pump if I ever had to replace it.