A critical part of the whole growing process is the germination and initial growing cycle of the plants. The quicker, more consistent growth of our herbs and greens from seed means we first of all convert more seed to plants, and also try to shorten the period of time from seeding to actual planting into the towers.
So, previously we had a misting system watering the seedlings. A few issues associated with this technique.
Due to the nature of the misting system, it was impossible to ensure that each of the 288 pods in a seeding tray was evenly and consistently watered. This is a major issue, as certain pods would dry out and we would therefore loose that seed.
Second, misting goes everywhere and therefore a percentage of the water is wasted. All the ground around the seeding area becomes wet, and all this water goes to wastage.
Lastly, as the misting system is from the top down, the leaves are wet. This introduces issues with the plants such as rotting etc.
The flood and drain technique is a far better process for watering our seedlings. Initially we will have 32 seeding trays being watered (that is 9,200 individual pods). The flood and drain system will consistently water every one of these pods identically, thus eliminating the dried pods and loss of seeds.
Secondly, as the water is pumped into a tray, and then drained back into the sump tank, no water escapes from the system, and therefore eliminating the water waste.
Thirdly, no wetting of the leaves occurs, as the wetting process is from the flooding water, and therefore only the pod is exposed to the water.
The design of the system is a 5 shelf wire mesh shelving system, with 4 flood trays, 3 LED strip lights per tray, a sump tank and a pump on a timer.
Each flood tray can accommodate 4 seeding trays. Therefore each shelf is accommodating 1152 seeds.
The sump tank is a basic plastic tub, with a capacity of 120 litres. In this tub is a submersible pump (with a 2m head capacity).
The water is then pumped to the top tray, on one side, and slowly fills.
On the other side of the tray, there are two drains, with elbows. They have been positioned so that as the water reaches the outlet, the trays are sitting in water.
The water then flows out through the drains to the next tray below. The drains have an elbow connection which positions a small tube to the bottom of the flood tray. Eventually as the top tray fills, a siphoning action starts, and the water drains out of the top tray to the next tray. This repeats down the shelves to each flood tray. The bottom flood tray then empties into the sump tank.
So, all that needs to happen is to fill one and a half trays with water, then let the siphoning action move the water from the top tray down and back into the sump tank.
We plan to run the pump 2 or 3 times a day, to ensure that seeding trays receive sufficient watering throughout the day.
Just a standard 120 liter tub from bunnings, will be the sump tank
One of the flood and drain racks is now complete. I have placed a number of seeding trays in the flood and drain trays and have run the pump.
All working well, except for a slight oversight. The tray have a slight angle to them so when you insert a tube it increases the water level height (ie the drainage height). I have over come this by lifting the seeding trays a little.
So I fill the top tray, and it starts overflowing into the second tray, let this fill about half way. Then stop the pump. All the rest is gravity and siphon!
On October 10th and 11th Bare Greens attended and sponsored the Bowral Home and Garden Show at the Bong Bong Race Course.
An estimated 5,000 people attended the two days.
We had a great response at our stall, showing off our system and our herbs and greens.
Sylvie gave two presentations at the Garden Pavilion and Frank gave one presentation at the Indoor Pavilion.
All in all, we feel the event was a great success, and was our first real attempt to expose our business to the market.
We are officially up and running, with silver perch tank water feeding about 140 zipgrow towers in the greenhouse. Over the next month or so, we will gradually increase fish numbers, and increase tower numbers.
We needed to setup a temporary fish tank setup as the rain has delayed the ground works and slab pouring. So we decided to setup one of the 5000L tanks inside one of our buildings. The tank is currently cycling, and once this is complete we will add the 500 silver perch to this tank.
Next we measured out the greenhouse pad, and determined the locations for the 20 piers.
The piers on the sides are all 450mm in diameter and approximately 1200mm deep. Digging was fun! We hit rock in most of the holes!!
Next step was forming up the slab for the fish house and then pouring the slab. The fish house is a 12m x 9m garage.
Due to the requirement that the water flow is gravity driven (returning from the greenhouse and fish house) we needed to complete some earthworks to create all the required gradients.
The water from the sump tank to the fish house and greenhouse is pumped, so this is under pressure.
We will provide BLOG entries to keep our customers updated on the progress of Bare Greens. Interesting information, herb use, recipies etc.
So stay tuned, or subscribe to BLOG update.