Here in Montana 2017, I could create the following iAVs ‘system’ for under US$7000 (excluding ‘greenhouse’, labor, misc. tools and related supplies):
24 m3 of circular conical-bottom fish tanks with top-quality stainless steel pumps, current state-of-art regenerative blowers (aeration) with top-grade ceramic diffusers, SS fittings etc., and coupled to from 150 to 200 square meters of sand beds. 45 mil EPDM fish/food safe liners throughout. (all equipment Made in US, btw).
0.5 HP, 11,500 litre/hour at 1.5 m head 0.67 HP, 990 l/min @ 1 m depth
That’s between $28 and $35 per square meter (including a 50 m2 tank area) or $2.60 to $3.25 /ft2 with ‘top-shelf’ equipment and materials. Okay, so, maybe add $500 to include some misc. items and delivery costs to my mountain. Would be $1000 less if using in-ground (dug/lined) tanks.
At an average of under $3.00 a square foot, that’s considerably cheaper than any empty Rubbermaid (etc) bin/tub from China-mart. Seriously! How productive could that be for you? What’s the cost:benefit ratio of a flimsy polyethylene bucket on steroids? Where would you plug it in? BTW, un-faced Styrofoam™ (polystyrene) is $1.56/ft2 (alone) at the local Lowe’s (building supply megastore).
At 175 m2 of ‘grow-bed’, planted as single-stem tomato (or equivalent), that’s 700 plants/crop x 3 per year with a minimum of 6 kg/plt, for 12,600 kg/yr plus an expected 1500 to 2000 kg/yr of tilapia. [ 100-120 kg/m3/yr is possible (has been achieved) ]
Before anyone asks, “Why don’t you?” 1) I’m broke, 2) have no GH or growing season, 3) have food and, 4) I’m old, tired, used-up and spit-out.
- Not available in stores.
- Itemized plans sold separately.
- Some assembly required.
- Batteries not included.
- Your smilage may vary.
PS: Ballpark cost for off-grid photovoltaic system to power the above equipment is in the $600 to $1000 range (PV cells, wire/fuse, charge controller and inverter) and without batteries (w/o aeration at night), base supports or installation. For 24-hour aeration (this example) add about $1000 to $1200 (for 500AH@24V for a 10-year +cycle/use life from lead-acid cells. Total overnight load in range of 35-45 AH draw (by latitude and season)… via the cheapest route … here … DIY)
- So, if it cost $1000 for panels etc with 25-yr+ life ($40/yr) plus about $110/yr for batteries. Effective annual cost $150.
- 24 hour load 13,5 kWh w/ 24/7 aeration. 13.5 x 365 ~ 5000 kWh/yr $150 / 5,000 kWh = $0.03/kWh. That’s about one-quarter of what grid electric rate is here. PV really has come WAY down in price over the past few years.
- Running cost (amortized PV) for 2 pumps (1hp @ 2hrs/day) is $0.045/day, $16.43/yr or $0.68 /m3/yr