Friday, September 16, 2011

15 - How Much does this Cost? Under $1000...


Here's a run down of the amount I paid for this system, with suggestions on how you can reduce costs even further.

Tanks - $440 - I was able to get the Rubbermaid stock tanks at a local farming coop for $70 and $80 for the 50-gallon and 100-gallon tanks, respectively. I think you'd need 3 IBC units to make something similar out of IBC, so that wouldn't save much cost. However I understand that it's possible to get 55-gallon barrels for free from local beverage processing plants. The downside of 55-gallon barrels is you'll have to spend more on plumbing, you'll have a lot more cutting to do, and the end result will look like hack-sawed plastic. But free is free.

Hoop house - $100 - If you use pressure-treated landscape lumber for the base, 3 mil sheeting, and 1/2" EMT conduit, the total price rolls in at around $100. You could slightly reduce costs for the frame by using PVC. Or you can decide you don't need protection at all, if you're in a climate that doesn't require protection from excess sun, rain, or cold.

Pumps and timer - $110 - I was able to find my 800 gph pump at a local hydroponics store for $60, and you can get an air pump sufficient to aerate 100 gallons for $30. Tubing and air stones round the total amount upwards to $100. One option is to dispense with the air pump, if you pump some of your water over the surface of the fish tank, oxygenating the water the way a pond fountain does. There are ways to use wind power to drive something like a rope pump, but I don't think that is cheaper than an electric pump (though awfully fun to make). I do use a timer to turn my water pumps off at night, which is another $5-10.

Plumbing - $100 - I used 3" pipe for media guards (4 feet), 2" pipe for bells (4 feet), 1" pipe to connect the tanks (10 feet), and lots of 3/4" pipe for upstands and drains (10 feet). Add in the elbows and adapters, caps, and o-rings and you're up around $40. I used garden hose that is drinking water safe to carry water from my sump tank to the grow beds, so two 50 foot lengths, adapters, and Y splitters ran me $60. You could reduce cost by having a simple standpipe and using a timer to turn the water on intermittently, though your water pump capacity may need to increase. As for plumbing between the sump and the beds, you could plumb that with PVC pipe and elbows. If you find a cheaper way to do it, after tallying all the costs, go for it.

Grow bed supports - $60 - I used cinder blocks (16 @ $2.50) and 2x6 planks (4 @ $5) to support the grow beds. If you are able to dig your tanks down into the ground, you can cut back on the number of cinder blocks required. If you can find such materials second hand, that'd be great.

Floating Raft - $40 - I was able to get a 2'x8' sheet of 2" extruded polystyrene for $15, and the 2" net pots cost $0.39 apiece. I suppose you could come up with some kind of wood float supported on empty water bottles and used (drilled) plastic containers.

Media - $ to $$$ - If you've got a pile of 3/4 gravel out back, this could be free. If you fill all four grow beds with Hydroton (@ $40 per 50L bag), you could be spending about $600.

So the basic system as I've got it here (including a floating raft bed) is $850. I love Hydroton, but I know of a friend who got an entire truckbed full (1250L) of expanded shale for under $60. So you can create an extended-season, vegetable-growing, fish growing water storage system for under $1000.

7 comments:

  1. What is the brand name of the extruded polystyrene that you got from Lowes?

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  2. The Lowes product I used is called Green Guard.

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  3. Meg, thanks much for documenting your build. Two questions:

    1) In this type of system (constant-level fishtank) the only outlet from the fishtank to the sump will be at the top of the tank. How is solid waste removed?

    2) If one of the beds is utilizes a floating raft, can fry be placed in there until they are large enough to be placed in the tank?

    Thanks

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  4. Hi Hans,

    I like having the outlet at the top, because that way the tank doesn't drain dry even if I have a leak at that point. But because the pipe in the tank is only open to water at the bottom of the tank, the solids from the bottom of the tank get vacuumed out to a certain extent. If I feel a need to remove more of the solids, I can always create a siphon with a hose that empties into a bucket/tub and 'vacuum' up stuff off the bottom. Then I can wait for the water in the bucket/tub to settle and pour the clean water at the top back in. Or I can dump the water into a grow bed, where most of the 'fish emulsion' can feed my worms and mineralize to feed the plants.

    You could certainly put smaller fish in the 'floating raft' tank. You'll want to have an air stone pumping air into that water, though, since a floating raft like the one I've got blocks the exchange of oxygen over most of the surface of the water. A good idea for the plants even if there aren't living critters in there, but even more important if there are fry/shrimp/etc. in there.

    Good Luck!

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  5. Thanks Meg! After reading all your posts (and watching all your vids) I feel brave enough to build my own system. Thanks for your work and please continue to post as much as time and interest allow.

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  6. Thank you so much for putting these awesome tutorials together! It has helped a lot...actually made all the difference in re: to the importance of a bell siphon.

    Added surprise that you're also from VA!

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