NO.
I was thinking you might have thought that.
The pump constantly circulates as you say, but the float is for keeping the pond full of water as the plants drink.
I even had a computer set up to mix up the correct dose of feed, to sit atop that float valve. So, instead of just water it would be food also. The weak link there was Windoz, and too many moving parts adding heat.
I mention that I moved away from all this. But, I think one of the keys to it is the square buckets. Round buckets, I don't know. It didn't seem to work well for me but I had other problems. Having roots in water is a constant migration of root pieces to clog pumps, and contaminate the living roots.
Pythium root rot is always present and can only be defeated by cool, oxygenated water. That is very hard to keep in buckets. It loves those warm air stones. Perfect foot hold.
Listen, many of us love to tinker. And I know small part sailboat plumbing,as well as house plumbing, etc. But, still, they say, water pond is not the place to start. So, of course, I started there.
But, besides tinkering, why do we even want a complicated, rig where the plants can't move? It is all the eggs in one basket and I lost plenty. All 12 of them at once, one time.
For me, now. I keep 4 pairs at 4 stages of growth. So I harvest about 1 time per month, and I root out a pair of new clones every month. 4 reservoirs at 5 gals each.
All the same food, but different strengths. No switch to bloom nutes. Just 16-16-16 Sea Grow, with some added Cal/Mag and Silica. I throw in some AquaSheild against the root rot and good to go. I just nug the tots on the floor with my foot to see if they need a fill.
So, still hydro. I feed 2 x a day 540ppm now for the ones that just began bloom. And I start the clones at 120 ppm.
For me just the ability to take all the plants out of the bathroom and tent for an afternoon of maintenance makes all the difference.
The plants go into 2.5 gal rose buckets at the beginning of week 3. They had 2 rooting cups, 16 oz SOLO first week, 6" azalea pot, the second week.
The 3rd week they go into the bucket with 50/50 coir and hydroton. Then they begin daily at about 240ppm.
From there they move through the system in the bucket.
Just another way to do it, that is much more simple for me.