Dedicated Spa Pump - Pump Never Fully Primes

[pigskintd]

I have a dedicated pump for the spa jet and the builder cannot get it to fully prime. Is this an issue? The pump basket has water a little past the basket, but I cannot see anymore because there are water droplets on the top so it blocks my view. The main pool pump is primed perfectly. The builder doesn't think it is an issue and we only use the pump for the spa jets. The water from the spa pump is either pulling from one of the spa main drains (we have 2 main drains and the pool has a inlet names spa mains. I know if it is only pulling from one of the main drains that violates the safety feature of the two drains) or it is pulling water from one of the lines next to the return line. I have not felt the line to the left of the return jet in the spa do anything yet , so I am not sure what it is used for. When I get home I can test if it pulling water when the jet pump is on. My main concern is the jet pump having air in it and not priming fully. What causes a pump to never fully prime?

 

[1poolman1]

If the jets work to your liking its not a problem. May need to tighten the union on the pump inlet. Don't use a big pliers, hand tight plus a little. The nut is easy to crack if tools are used. Make sure there is lube on the lid O ring.
Why is the spa low on water? Its not good for the plaster to be exposed like that.