Bonsaibelly wanted an expandable system that he could add to later, so he decided 2 IBC’s would be better than 1, as well as 2 blue barrels cut in half lengthways. It didn’t take much effort to wash out the barrels which had been used for storing glucose. The available space is 4 metres x 3 metres wide narrowing down to about 1 metre.
He ended up using poly irrigation piping which is more expensive than pvc, but easy to use. It screws together and you can snip the pipe easily with secateurs. Another brainwave he says “I thought that if I bury the IBCs, I wouldn’t have to build racks for the 1/2 barrels, as they could be supported across the top.” He now has 4 barrels on top of 2 IBC tanks which means there is lot of water capacity, though not many grow beds. After getting about half a metre down, the dirt turned to rocks and then to super thick clay which was impossible to dig .
He says “Oh well I figured that it is easier to build a step, than to dig deeper. At present the scoria filled growbeds, are at a height of 1.2m.”
He has connected the tanks 50cm above the base with a pipe and tap. The pipe sucks from the bottom of the back of the non pump tank and runs via connection to the pump tank. As the water drains from the pump tank it gravity feeds from the other. The idea is the water is gravity forced from the bottom of the non-pump tank helping cycle the water from the bottom up. It is actually a pretty slow feed but seems to keep up.
He added a tap just in case there was the need to isolate the tank later. The pump tank will drain around 300 litres per cycle. If the system is to be expanded later he can see there may be the need to add a sump tank to maintain a more steady flow in the 2 tanks but it will be fine initially. At 50cm if there is a pump blow out when he is not around, it can only drain the non-pump tank to that height.
The pump in the fish tank comes with a float switch which has been secured at a height maintaining a minimum water level of 50cm, another form of backup in the event that something does go wrong. Bonsaibelly like many others does not want to come home to a dry tank and dead fish . The 400 watt submersible pump has more than enough power to get 3 more barrels going in the future. He says “I am happier with the pump and timer system- it just seemed a little less complicated and I was a little scared of auto siphons. I saw pictures of drain and overflow by Food&fish and ‘referenced’ that pretty heavily.
Anyway the water is pumping through, now with beds filling in 3 minutes and draining in about 35. The pump runs once per hour, 15 minutes on, 45 minutes off, which has been pretty good. It is great going out and hearing the timer kick on, on queue.”Seedlings were planted in the media filled growbeds and a little seasol was added to give them a boost. Trout were then introduced and grown to plate size before they were harvested and served to some special guests. Bonsaibelly says “We had sushi with trout from the barbie. Yummo! That led to a small success – my 12 year old niece was over, and is usually pretty fussy with food –won’t try new things but also suspicious on mass produced cow and chicken etc. I got her to try some trout – promised it was super fresh and pretty much organic. Great to see kids try new food.” A variety of produce can be grown easily including fruiting crops such as tomatoes, broccoli and peas. Leafy greens also do very well including English spinach, silverbeet and lettuces.