Look ma no air! I love it! looking good there Sub. How often are you changing the res.? I have noticed in dwc that if you keep the ppm just right your ph stays stable. I remember the first dwc grows and the ph was all over the place. i was worried about lock out with a high ppm, lol ohhh the things you learn.
i plan to change the buckets approximately every 2-3 weeks or sooner if needed.
so far the water has been quite cool. DWC reservoirs get alot of heat from the air pump, believe it or not. I plan to cut out some cardboard to go over the buckets to insulate them from the heat of the light
They all look healthy, first thing I noticed was no air I dont grow hydroponically but was curious how long they can last that way. I remember one you did before with no air but didnt follow close enough to see the process. watching you grow is like watching Bob Ross paint. Artist in there element.