Smelly, WOW, your busy cuz
I love all the stuff you got, and 2 elbows e'ry 2 months is some goal! You'll get there
Look up JigFresh's hydro setup if you havent seen it yet
It is truly inspriring, and can be small scaled if need be
For what its worth I have real good success with flushing every week. I do my hydro girls like this and my soil. I only have 9 ounce cups and 2 quarts for MOM, but they can get salt build up too. I pour about half a gallon through each cup, then put 'em in the rez 3-4 hours later.
When you do your clones naked like that you can put them right in the net pot with very little medium. The stems/roots will fill it in pretty good, you just have to prop it up and cover the hole to protect from intense light
Good info on the meters too. I need to pick up some calibration solution and calibrate. Thanks smelly and someguy