OK,here it is....now bear in mind these are prototypes to proof system on the bells,final instead of plastic bottles the bell will be 2 or 1.5 inch pipe.
It is made of 2 parts,the standpipe on right of 1 inch pipe that goes thru the bed thru the black bulkhead fitting.The clear plastic bottle is the bell part.Ignore the skinny black tubing,another story on breaking siphon but I think I can get away without it.Note water level about 1/2 way up,it needs to get to top then creates a siphon to drain bed.
Here is a siphon thats siphoning,sucking water into standpipe and out thru pipe into water tank.When it reaches bottom of bell,it sucks in air and breaks the siphon suction,pump refills bed.The problem was starting suction.It takes 14 lbs of air pressure between top of bell and top of standpipe,with my low volumes I couldnt get a siphon started,it just drained in as fast as pump brought in water.Found 2 tricks,get top of bell to within 1/8 inch or so of top of standpipe,making creating that air pressure easier,and putting a slight angle on top of standpipe,why that starts it better,and stops it reliably I dont know,it just does in this setup.
The next problem was the pump.The plan was pump would fill one bed...
I was going to connect the beds by a pipe side to side on bed,thru black bulkhead fittings,then tee'd over to other bed,as water seeks its own level,using just one pump and one siphon to fill and drain 2 beds but 2 problems....1 it didnt work well,and 2 its exposed to freezing weather and freezing and plastic pipes just wont work...Top and bottom pic of pipes.
Ignore white pipe,its just sitting there.The bulkhead fittings will be plugged and pipes removed,just didnt work
This is how pump works now,feeding both beds,and a bell siphon per each bed.Dont know if air pump has enough air to run 2 water pumps,1 per tank,we will see.
Note downspout has a little water container at outlet,without it you hear the rushing sloshing water as its pumped and also air escaping,it is truly loud and a big muffling effect doing that,so downspouts will have a water seal to drain into.
Another 62 dollars
Nice to be moving forward again!