Based on the experience gained after my first attempt, I estimate that 18 x (0.4mm) Misting Heads (NM40BH-HF-U1) from "CoolMist Systems Australia" can be used with a 10 Gallon (32 Liters) Accumulator (a.k.a. Pressure or Bladder) tank, connected to a 110 L/min, 6.2 bar (58m head-height) water pump, which will draw water from a 120 Liter Container (Bunker Tub). I'll be using Canna Bio Vega (1 Liter) and Canna Bio Flores (1 Liter), Organic nutrients that smell strongly of Vegemite. The concentration the first time was 650 ppm. The story of my first failed attempt goes as follows: About 14 Watermelon seeds were propagated in a mini green house filled with soil. I turned a 2nd hand 200 Liter drum (My hands became swollen when washing out the engine coolant) upside-down and cut the bottom off (Very messy). 14 holes in the same shape as the square 50mm pots (This was all I had at the time) were cut into this bottom, which was now the Lid. I did this, because it was a closed-lid Drum. 6 misting heads on Nozzle Couplings were connected together as a loop made of 3/8" nylon tubing, which didn't properly fit the inside of the Drum. The 'Lid' of the Root Container was also slightly ajar due to how it was cut by the grinder. The Root Container sat upon the Bunker Tub which had it's lid off. The excess water from the nozzles spay would drip down through one of the Drums bung holes (Which used to be the top of the Drum) and into the Reservoir (Bunker Tub). Because the Reservoir didn't have it's lid on, it was exposed to sunlight and air. Due to the improper sizing of the Misting Loop, the stressful transplant of the roots from geoponics to aeroponics, and the lack of biological control / aeration of the reservoir, some of the plants died while the others got root rot. Then, a big nasty -3 degree frost comes along and kills whatever plants I had left (Winter temperatures in the desert). Now, for my 2nd attempt, I'm going to buy 3 x 200 L 'Open-head' Drums (BR) for about $700 and have them sit on a metal-screen bench, above the reservoir so that the excess can drain back into it (Through a hole in the lid). I still want to use the organic nutrients but this time with beneficial bacteria. I hear that products for aquariums are cheaper and just as effective, but will I also need to aerate the reservoir with an air-stone? Since the lid will be on, any extra air will travel up through the garden hose tubing that drains excess water from the Root Containers, and then, through the new 75 mm wide net-pots filled with 50/50 Coir and LECA. If I add the Beneficial bacteria (API Stress Zyme) and keep them alive with an air-stone, will I still need to empty the reservoir after 2 weeks? I'd really rather not, as the nutrients I'm using are very expensive ($130). I assume these bacteria will die after a few hours within the Bladder Tank (6 bars max), but will that be a problem for the roots? As for why the frost got them, I had only used one layer of Horticultural Fleece. P.S. The timer Schedule will be 3 seconds per 3 minutes.