It might be a tad warm. My water temps were right at 70 for the beginning of my grow. Just lucky as I didn't have to do anything. Now that I am in the Frozen Tundra my temps are in the 60s. I think that is why I am getting very little flowering stretch. I know soil plants like Roots zone temps in the middle 70s. (veggies at least) I would figure hydro plan it's would be the same. I think I am doing soil this time around. So, I will have to do another hydroponics grow this summer and put ice bottles in the res during the 1st few weeks of flower and see if that limits stretch. I was hoping for more stretch as my plants were shorter than I wanted when I flipped. My large plants has only grown 5 inches in 2 weeks. Currently 17 inches tall. Was hoping for 32-40 inch final height. Be lucky to hit 24 inches at this rate. Lol. It's probably a good thing tho, as I have no idea what to build to support the colas for each plant.
Stay well.
Madman