Thanks guys
Dave I understand the tank will be the sump and each grow bed will take it down about 1" so even all 4 at once would be 4" so that doesnt bother me too much . As for the 2" if thats the biggest problem I encounter it's all good I also have a bunch of 2" laying around from my spa days that's what made that choice .

Stucco Are you saying 1.5 for the bottom of the bell or on the main drain line ? The trap part I understand and am guessing thats to prevent to much air in the line breaking the flow.

Bad Yes one siphon per bed and I thought from what I have read that 1" should be ok for that sized bed , yes ! I know basicly it is sewage and I had planned a clean out on both ends . I was wondering whether it needed a straight drop or you could do a P-trap type coming off .

See that's what I mean if the water level is 16 " above grade the bed is 16" deep ,I drop 6" with plumbing ,then give it another couple inches for drop in the run . All that adds up to 41 " which is a bit high for the top of the beds . Then I have to put two beds beside each other ( so really is a 6'x6' split bed ) It becomes very hard to reach the inside plants at that height . I was hoping to figure a way to get the beds down with out redesigning the whole system . I was hoping for a simple fix ok at least one that did not entail this old man digging anymore rock ,Rock sucks !
It is looking more and more like digging may be the only solution
Have A Kind Day
Mike