I have a 94 clearwater spa, mfg in Woodinville WA. Originally came with a grunfos circ pump, replaced with a Laing which failed and was replaced within a year with another Laing. Upgrading to a Aqua-flo circ-master based on mfg suggestion. The tub is located at a vaction home which has frequent power failures, after which I find the tub with a constant flo display. Balboa spa pack. This tub has been prone to FLO problems, possibly due to design flaw. I drilled a couple of extra holes in the filter top which decreased the frequency of FLO problems except for the power failures. The mfg service dept says the Laing pump has issues with repriming itself. So, the new pump is on the way. Any suggestions on how to plumb this thing in so as to avoid air locks. See photo attached for existing circ pump plumbing. I am using the recommended filter which is a less restrictive variety.

Plumbing to Left of pump not shown is a straight run to filter. Top left of heater has a tube [bypass] running to a cluster of three small heater jets in the spa. Flow switch is located on right upper side of heater. Heater runs straight to 3 heater jets below seat in the spa.

I am wondering if I should add another small jet outlet in the seat to provide better flo?

Photo with gate valve shows plumbing form heater outlet on it's way to three small jets in tub.

Oh heck no. Once you put a REAL pump on that thing all of these problems SHOULD go away. The GPM rate of the circ master is huge compared to a standard microsized circ pump.

You're going from ~7gpm to 40+ gpm with the pump upgrade.

(420 GPH vs 2400+ GPH!)

Install the same way and step back and enjoy a life without flow issues.