Backyard Aquaponics
A place to discuss aquaponics

Added a link for some info ....

http://www.biosub.com.au/Down%20under.htm

April 4th was the official starting date.... yesterday. looks interesting...

I heard him on the radio talking about it

hay does running the water clock wise work better than anti clock wise or vice versa

I thought i`d share a crackpot idea i`ve been playing around with for a while, just for giggles really but you might find some aspects interesting.
I`ll let you decide..
The basic idea relates to vertical systems which seem to be quite popular. The main potential downsides are clogging and uneven coverage of the medium. The upside is a potential multiple increase in growing area vs footprint when compared to a flat bed.
An 8ft dia bed has ~50 sqft surface area and 25 sqft circumference for every foot of height, so the side of an 8ft dia bed x 2ft high will equal an 8ft dia flatbed. Making the bed 4ft high will double the area.

If the vertical bed is circular and constructed with a 12" deep cavity wall you will have 8ft outside dia and 6ft inside dia, the cavity iteslf will contain the medium (hydroton for instance.. about 100 cu ft)

Ok, so lets say this 8ft round x 12" thick hollow cavity wall is 4ft high, you have 100sq ft of area at the wall which increases as the plants grow outwards into space..less crowding which is a plus.

Assuming you have a round fishtank big enough ..there`s no reason why this vertical bed can`t be placed directly in the tank.
With sufficient bouyancy it will float ..which leads me to the next bit.

A "floating" circular bed has the bonus of being able to rotate without a lot of friction, noise or power.

The ability to rotate the bed has the advantage that every plant on the side of the bed will get an equal share of the available sunlight and shade throughout the day.

The rotation of the bed constantly moves air over/through the entire canopy for better gas exchange.

Lastly the irrigation issue,
The medium can be evenly sprayed as it the bed goes around via a spraybar located above the bed (the spraybar doesn`t move..the bed does)
Due to the time taken for one rev ( maybe 1 rev per hour) there will be an automatic drying period, alternatively spraybars can be added around the top circle if required to increase the watering frequency.

The driving force for the rotation could be a cheap antenna rotator (~1rpm) plus simple gearing (~60:1) which should provide more than enough torque and turn the bed once an hour.

One pump, one rotator and gravity drain back to the tank.

So there you have it, a bit mechanical granted, worthwhile..who knows.

I`ll let you be the judge

Hex, what drains the water out of the grow media, ie hydroton...??

or is this just like a giant circular donut shaped floating raft with the roots growing through into the tank.....

Would work OK...IF you kept it REALLY WELL oxygenated....

Well, if space were your most limiting factor, it might be worth doing. You wouldn't need much torque if the growbed floated very freely. But how do you harvest the plants on the inside of the donut? Don't tell me you're wasting that space?!?

Hex stirofoam would be a great media for system such as this,
even to make the grow bed out of. it floats!!!!!!!!!!!!!!!!!!

If the space inside gets sun light that would be a nice extra space once you can get inside to care for the plants

hey give the grow bed a hub and you can rotate it useing the power from the spraybar.

Thanks for the replies, it not likely to be built but it doesn`t cost anything to explore the possibilities

Hi Janet,
I did consider the inside area, but as the plants would be growing into an ever decreasing space the plants lower down would probably get starved of light.
As the space filled up, you might get damp/ mildew problems too due to lack of ventilation too

Having a small footprint is good but it seems to me that if the sunny side of a bed is more productive, those plants will shade the ones behind and hinder growth somewhat. The rotation could even out the growth nicely.

Hi Rupert,
I visualise the bed as a 8ft dia cylinder with a 12" wall thickness. The wall is hollow though.
The bed is fed from a fixed point at the top so you`d have a downward spiral flow as it rotates it wouln`t fill up with water like a FD bed.
The bed is full of air most of the time so aeration isn`t a problem.

The roots shouldn`t grow into the tank, even the very bottom "ring" of plants have a 25ft long x 6"deep x 12" wide area to explore ..12.5 cu ft of medium. Unlike a tube system the roots should have plenty of space to roam around in.. downwards and sideways

Hi CG,
The spraybar is fixed and it sprays downwards onto the top of the medium, the bed shouldn`t need a hub if it`s in a round tank.

If you angled the spray bar and used a few hundred psi you might get it to rotate ..bye bye hydroton though lol.

Logically the inertia would gradually increase the rpm of the bed and reach a speed where it begins throwing your plants all over the yard..like a spin dryer

would save on harvesting time

No Steve, easier/lazier to harvest....just plant your blot on a comfortable seat and wait for the AP merry-go-round to bring the produce to you....invite Axl & J (with their home-made alcoholic drinks)

OK, I found it....

http://www.4hydroponics.com/hydroponics/volksgarden.asp

You would have to eat a lot of salad to justify the price tag. Bad thing is, no fish to watch!

WOW. That would be a real space saver! And take full advantage of the light.... Interesting thought -- F&D with no pump -- move the plant, not the water.