I'm in the planning stages for my system. Our climate tends to be mild for our latitude (45°N) with typical high temps in the summer near 30°C and lows in winter of 0°C. Highest temps are closer to 40°C and lowest are -15°C. The system will be located outdoors and will eventually have a greenhouse built around it.
I'm thinking of using two IBC fish tanks, buried about 2/3 to help keep temperatures stable. There would be a ladder rack of 10cm pipe drilled with 7.5cm holes with the rack tilted 45° from vertical over the fish tanks. Pipes would be 3m long and angled enough to give a 7.5cm drop on each (which means about 12-13cm drop if the rack were vertical). There will be one or two grow beds either at one end or in front of the ladder rack to give plenty of space for bacteria to do their thing and to allow for some bigger plants. I might also seed these with worms. I'd expect to use a swirl filter to remove the bulk of the solids.
First question, could I trench between the two fish tanks to allow for water circulation between them, give some shallower area for water plants and possibly give a safety zone for fry (hoping for trout, may settle for bluegill or crappie)? I'd like to get the fish self-perpetuating as a 'nice to have' goal. The word 'trench' is a bit of a misnomer here, since it'd actually be an elevated roadway, about 1/2 of the width of a IBC and about 75-100mm in depth...
Next question, ignoring oxygenation needs, could I pump out of the bottom of one fish tank and deliver return water to the bottom of the second fish tank, setting up the flow through the trench? I'd have to add bubblers or spray wands to add oxygen to the water.
Another question, should I use two pumps, one from the FTs through the SF to the GBs, drain the GBs to a sump and pump from there to the top of the ladder? Or would it be better to pump through the ladder, to the SF, then GBs and finally to the FTs? We're talking two rises, one of 2m (bottom of FT to SF) and a second also 2m (from sump tank to top of ladder) or close to 3m of head in the 2nd scheme. I expect either way I'll be using piping between 25mm and 50mm for the pressure portion of the cycle.
Finally, can I stress the PVC enough to angle the joints the needed amount to give my 40:1 drop I'm planning on? Or am I asking for fatigue cracks over time?
Really finally this time... What am I forgetting? I'm planning on going the arduino with sensors route to gather data while running, even if it's still not viable to measure ammonia, nitrite and nitrates (here's hoping someone will kickstart a 3in1 sensor for that soon) I can do a good job of monitoring temperatures, possibly Ph, and alarming flow issues. It'd also be kewl.
Backyard Aquaponics
