That's one gorgeous flower! The water drops enhance its beauty, too. You didn't strike out --you hit a home run!

Could air in the system cause this problem? Yes, it is. The water turbulence, is caused by a lack of backpressure. What type of heads do you have? Impacts? Could this be caused by a slow leaking head? Yes, it is being caused by water draining out of the zone. One that is lower than the other heads and the valve? Yes, that is how a siphon works, and drains a zone. You need to find out which head is failing to pop up. Some heads (impacts, and some rotors) allow more water to escape before they are fully extended. This means, that the zone then uses more flow, than available, and never developes enough back pressure to fully lift the heads and clear the air from the lines. I would replace all the heads on the zone first, after I was sure there are no leaks or defective heads. Second is the valve.

One of 3 things. 1) The spa shell is leaking either at a crack or a fitting such as the edge of a drain or a jet. Not real likely but possible. Possible but not really likely. Would require emptying the spa and checking the edges for gaps and cracks. Finding them means verifying with either a dye pen syringe (had a 3" tube to reduce currents) or food coloring to check if the spacing are drawing in water. 2) Check valve flapper's gasket is out of shape or there is debris at the edge. Most likely. Empty the spa below the jets and remove the 8 screws so you can pry the top off and look. Use a #3 Phillips to keep from marring the screws. 3) The valve in front of the pump is leaking. Not likely since NeverLube valves tend to be pretty reliable. Requires lowering the spa to pool height and removing the 8 screws holding the top of the valve. I am assuming the equipment is above the water level and below (requires the pool and spa be plugged, drains too). I know the actuator is attached to the valve. Use a #3 Phillips to keep from marring the screws. Scott

I disagree that the unwashed masses would not notice that a sink is not undermount. If the neighborhood warrants quartz counters, a significant percentage of prospective buyers would notice it and find it not as appealing as undermount. Before I knew anything about kitchen trends, I knew that I hated wiping down a counter with a sink that was not undermount. But as Sophie wrote, renovating to sell within a short period of time is probably not a financial jackpot absent unusual circumstances or ones’s ability to remodel at significantly more savings than the average person. I had friends who did high end remodels but they were both realtors who scoured their market for undervalued homes in upscale neighborhoods and essentially had a crew of people that they kept busy so there were no surprises in terms of attempting to find labor or spending endless time researching the best prices and of course they were contractors for their projects and got the benefit of those kinds of discounts.