Where is your overflow to prevent a flooded room and as far as veg and flower times, veg is up to you based on what size plant your system will support which doesn't seem to be huge, and flower is determined by strain genetics not opinion, conditions change the duration but only by a few days difference.
Id grow 20cm clones and zero veg in this set up, i.e 12/12 straight out. No veg, lighting 400 watt hps.
Lower light to 25,000 lux first 3 weeks then lower to 45,000 lux, download a free lux light meter to your smart phone.
Flood once every 3 hours in light and dark and run a 5 watt air stone in the tank.
Should work fine, you will need a 24 hour digital timer.
Dont flood the top 4-5 cm of hydroton, doing so will encourage algae and other pests like gnats as well as drying nutrient salts, you dont want this.
You dont have room to veg so your zero veg turn over will be 8-9 weeks.
You need to master growing strong clones prior to planting, you could veg one week under a halide or 125 watt CFL prior to planting. . outside of the system.
It will work great. (if roots don’t strangle your pipe) use a gauze 3-4 cm above the pipe)
As mentioned above think about your overflow protection, this could be your digital timer , it will have to turn off in the seconds it takes to flood at the correct level.