Free Flow, we all have personal preferences when it comes to hydro systems, and frankly, I've tried almost all of them. A straightforward ebb and flow table is hard to beat for flexibility and simplicity. DWC - not a huge fan due to the challenges of LST training, and the messiness of nute changes. RDWC fixes practically all of those problems & makes temp control easier as well. Aero - real high pressure fogger aero - expensive and prone to problems long term.
But by far my strongest performer has been a simplified version of the expensive and complicated Flo' n' Gro system. Professional systems of this type typically run in the $500-600 USD range. They work great with all the advantages of this type of system, but (a) they are expensive and (b) the complicated timers, valves and manifolds are a PITA to maintain long term. The one advantage of this system is that the complicated manifold allows you to place your plants on the same floor level as the reservoir.
But - if you have about 14 - 15" of vertical room to place your tent and a manifold on top of a small home built table, which sits over your reservoir (Rubbermaid or Home Depot's house brand) you can fashion a very simple, reliable and top-shelf functional system that IMHO performs the best of any flood and drain system on the market.
The strengths of this system are an enclosed net pot which prevents root exposure to light & discourages evaporation, and the ability to perform frequent flood cycles. The flood cycle frequency is important because as the pot floods, it pushes stale air out of the root zone. As the pot drains, it pulls fresh oxygen back into the root zone. This, coupled with an air stone in the reservoir, assures a super oxygenated root zone at all times.
The only moving part of this system is a fairly small hydro pump. I've settled on 190GPM as a great size. And ECO Pump brand, I've never had a failure. Assuming you don't move around individual components and disconnect a hose, the system is almost fail safe and practically impossible to create a leak or overflow. In about five years of using this system, I had one leak - a small capillary leak where I cracked my manifold bucket moving it around. The system is so reliable because the pump feeds a manifold bucket, with an overflow tube that sets flood level in the growing pot. The premise is like a water level - the level in the plant's net pot container physically cannot exceed the level in the manifold. Roots will never cause a clog in the Flo n' Gro net pot container because the feed into the container is under pressure, which washes all roots INTO the net pot. Drain is passive by gravity only. Might sound a bit complex, but take a look at this hand drawn schematic & it will make much more sense:
You can purchase the 4 gallon Flo n' Gro container ($7) and 3 gallon net pot container ($7) from Sunlight Supply, pre-drilled with grommet installed for a 3/4" hydro fitting. They used to sell a 4-pack expansion for their Flo N Gro system at a discounted price from that, check and see.
I've used this system for many years and it's a reliable winner. Week long vacations are a reality with this at home doing all the work for you, and yield is stellar.
Here's a shot of what she looks like assembled:
Shout if you need more info, I've probably got more data lying around somewhere.
lol. I keep hoping for a Male from a decent genetic line but all I keep getting are females. Lol 
