Earthship aquaponics plan

[marcandfiveones]

Hi, all! this is my first post. I'm currently studying in New Mexico at the Earthship Academy. For those who don't know what earthships are, they are radically self reliant, off the grid homes using many technologies integrated together eliminate utility costs almost entirely. My plan is to build a simple survival model earthship, with rainwater catchment, filtered through botanical cells and then into a tilapia pond, and then recycled back into the planters to create an aquaponics system. I know that some earthships have featured rainwater fed tilapia ponds, but as far as I know they haven't experimented much with aquaponics. It seems like it should be very easy to integrate the earthship greywater planters into a cycle with a tilapia pond, but I have a few questions to start on this path.

My floor plan currently would ideally have an 8 foot deep, 2 foot radius cylindrical tank at one end of my planters (750 gallons)

My very brief research implied I needed more length than depth to get proper water flow.

Is there any way of making a tank of this shape and orientation work with proper pump placement???

any advice?

here is a floorplan, the tilapia pond will go where the toilet is indicated on the drawings. I will be doing a composting toilet rather than septic.
Image resized by admin. Please refrain from posting graphic of such large sizes.
http://diyaquaponics.com/MyImages/149copk.jpg

[Eleven11]

I'm a big fan of Mike Reynold's. I think the whole EarthShip type community thing is a great idea. Sort of like intentional communities.

Seems like a tank that size and dimension would make it hard to work with. Will it all be above ground?
Other than higher head pressure, what other problems were you expecting with water flow?

[Oliver]

My floor plan currently would ideally have an 8 foot deep, 2 foot radius cylindrical tank at one end of my planters (750 gallons)
Surely you meant 2 foot deep and 8 foot in radius fish tank!

Sorry, but that is not realistic either. For raising Tilapia, you will need several much smaller (2 to 3 feet deep) fish tanks and grow them out a few at a time. Also, you will need a separate breeding and brooding tanks. Tilapia have built-in transporter technology as I have seen them disappear from the part of the tank where my fish net is located and instantly reappear on the other side of the tank, and that was in a small shallow two foot deep stock tank. Imagine either an 8 foot deep tank or one that is 16 feet in diameter. You will need a built-in bottom net in order to hoist them out, which can be done.

Oliver

[foodchain]

Why is that not realistic? Sure he would need smaller tanks for the breeders. But there's no reason that the large tank wouldn't work for growout. Or keep them all together and use a grader to sort specific sizes.
Something this size try using a cast net, or net dividers/partitions. I have had great success with the larger cast nets with 3/8 holes.
Yes it requires effort, but beats draining it all, and I am only looking for a handfull at a time anyway.

Surface area is far more important than depth.

[Greg]

From everything I have read, you need proportionally more depth to width for success in raising fish. you may need to find a compromise between what is optimal for fish and water flow. I know the topic here is aquaponics, but I also see an integration between earthship design and solar chimney technology. The rain catchment design of the roof could be double layered with the outer layer being glass, lexan, etc for a greenhouse effect which induces a thermal updraft that can be coupled with a conventional windmill for enhanced performance. with aquaponics and a thermal updraft incorporated this becomes a little more like an "earth" ship.

[bcotton]

From everything I have read, you need proportionally more depth to width for success in raising fish....


Did you mean to say more width to depth?

brian

[Greg]

Negatory, For success in raising fish the water needs to be proportionally deeper than wide. An exception to this, naturally, would be a very large body of water that has sufficient depth no matter how wide it is. I do not remember the exact source of this info., but I learned this while perusing thru Youtube vids.

[bcotton]

Where did you get this info? This is not true.

Most aqariums from 2.5 gallons to 100 gallons are wider than they are tall. Why would that be if fish need deeper water?

I have had great success growing fish in wide water 1-2' deep.

brian

[Greg]

Most aquaponic systems, unlike aquariums, are outside - subject to freezing temps, predatory animals, etc......

[bcotton]

it's still wrong,

just look around the member systems section a look at all the people using rubbermaids, swimming pools and stock tanks... the one i use is 5' diameter by 2' height.. outdoors.

brian

[keith_r]

i've seen a few people use tanks that were quite tall and buried, but they don't allow the fish much swimming room imho.. but the only reason you need surface area is for oxygen transfer.. if you can pump air down 8', that wouldn't be a concern
the other problem with a "deep" tank would be that you could get a "thermocline", and in a water turnover, your temp could swing drastically and cause stress/fish deaths.. i don't think you'd have that problem with an 8' deep tank though
be kinda hard to catch the fish without a good net system too

[2600knurd]

I have only one other thing to add about the depth (from the engineers reading this)about deep versus wide.

If you are looking to keep a large amount of water, it is cheaper to build a 2' high tank that is 8' wide than it is to build an 8' high tank that is 2' wide. The reason being the amount of pressure 8' of water has, you would need an in-ground tank or some serious structural reinforcement.

Example: Take a hypothetical ridiculously-size aquarium that holds 76 MILLION Gallons of water.

Option 1: 3280 feet (over half a mile) square by 1 foot high (so 3280 x 3280 x 1)

The glass thickness would need to be about 0.2 inches! LESS than a quarter inch.

Option 2: 820 feet by 1641 feet by 8 feet high (820 x 1641 x 8)

The glass thickness would need to be about 4.1 inches!

Now, I know what you are thinking: "But I don't have 76 MILLION gallons. I only have 1,000 gallons."

Option 3: 1 foot by 1 foot by 8 feet = (~56 gallons)
Thickness required about 2"

Option 4: 4'6" x 4' x 8' =~1000 gallons
Thickness required about 2"

These calculation are for glass. But the concept of needing more strength for deeper water remains no matter what material you use. In-ground tanks will be best.

In summary, my 76M gallons from my Option 1: (over 300 Ml -- That's MEGALITRES) requires walls with a strength of X.
My Option 4, 1000 gallons (~4 kl -- kilolitres), requires walls with a strength of 260X (260 TIMES the strength) to hold 1/76,000th (0.001%) the amount of water.

Enjoy the thought experiment!

[badflash]

This is all conjecture as far as how deep vs. how wide. It would also have a lot to do with the type of fish you choose. I have very successfull rearing in 100 gallon stock tanks, and 20 gallon aquariums, 55, 90 and 110. All my systems have been close to 1:1. Tilapia send to spend their time close to the bottom, so the water above them would be mostly wasted.

I'd need to see some studies before I would go for any one design.
Tanks 8' into the ground would have a lot of thermal moderation. Aeration at the bottom would keep the temperature pretty even. 2' tanks don't give a lot of swimming room though.