Backyard Aquaponics
A place to discuss aquaponics

Cool, wrong again for me LOL, but i keep yas on ya toes huh?

Can't be 100% right all the time... I figured you actually just wanted someone to go and look it up and give a link to the reference material, the way you said that you "weren't 100% sure, feel free to correct me".....

busted again! you guys are getting to know me too well

After reading some more on the forum, I'm planning to incorporate CF some strawberry towers into my system -- on the north wall of my greenhouse. If all goes well, I'll be able to compare the towers with my F&D gravel media growbeds and the raft culture. Nothing scientific, mind you... I have a hunch that certain types of culture work better for certain plants and perhaps even certain growers.....

I guess the way I like to think about agriculture -- learn what can be done at the extremes and then look for a way to find an inexpensive middle ground that requires less work.

Another thing worth considering is the cost of the growing bed vs area.
FD needs a watertight container strong enough to handle the weight of the gravel and water.

A CF bed doesn`t have to hold as much weight so it will be cheaper,and easier to homebrew, plus your not limited by the container sizes/shapes available.
You could make the bed 200ft long if you wanted to

I opted for CF in my basement because I didn't want the levels in my aquarium to be constantly changing from full to almost empty.

I guess each type has added benefits for different situations.
Continuously flooded adds to the overall volume of water in the system.
Constant flow and continously flooded keep the fishtank level relatively constant.
Constant flow (trickle/drip) could be designed to provide additional aerated rootzone space and also give an NFT twist to the proceedings.
The only downside is getting even coverage of the medium and that the pump would run longer (possibly 24/7) than in FD, but i guess that`s no biggy though as it also helps aerate the water.

Swings and roundabouts

Very true,but you still need the appropriatly sized bio and solids filter, i attended the open day at Dr lennards facility, and i can tell you, the bio filters were HUGE, and i mean HUGE, they had a cat walk at the top from memory, and also seperate screen filters for the solids that were clean 2x daily. Oh, and the swirl seperator too.

Each system has its merits, just dont forget a CF DWC aint gonna be JUST that.

Steve

Hi Steve,
I`m leaning more towards constant trickle flow down through the media bed rather than a constantly flooded medium or plain dwc. I think the former may have a lot of benefits.
Here`s the plan:
The bed can be made from plain old 2x4 timber (simple rectangle for example)

Fix a length of black and white poly (black side facing inwards) to the side rails such that it forms a loop (a "U") this is the water return "duct".

Fix a length of shade cloth (or plastic mesh small enough to prevent the medium falling through the holes) to the side rails and let it form a loop somewhat smaller than the b/w poly loop.
Fix a narrow lengthwise strip (~6") of b/w poly to each side rail and position it inside the the mesh/shadecloth trough to prevent the waterflow from going sideways too near the top of the medium. Think of them as side shields to direct the water downwards.

You now have a mesh or shadecloth trough for hydroton contained inside a poly trough seperated by an airspace.
Water flows through the hydroton, drops down into the return duct and back to the tank.
As the roots grow they exit the medium trough and hang in the airspace of the return duct (water will still travel down the roots too)

If (when) they make it to the bottom of the return duct you will have something akin to NFT.

Even coverage is the only bugbear, after that it should be all gravy
Shadecloth and b/w poly costs next to nothing so it should be inexpensive, the hydroton will be the pricey bit.

You might get away using gravel but it would depend on the shadecloth or mesh strength as it holds the weight of the medium.
The poly trough only needs to handle the return flow water weight.

You could also stack these troughs up vertically on a frame or perhaps even hang them from the ceiling using chains.. bondagaponics

Not that I totally understand what your planning (I think I do) but I like it. Main reason is that it is different. I was talking to EB a few weeks ago and he said that AP had got a bit standardised in North America then there was the gardening Australia Story on his systems, then this website and forum and then......

an explosion of inovation. He sounded that one of the things he was most pleased with was the variety of configurations and system components that people had come up with and where then all contributing to the public domain.

Stuart

EB
If thats wrong EB please correct me. Wouldn't want to misqoute the guru.

Yep, I said something along those lines.... These discussions are helping to move aquaponics research forward in enormous leaps and bounds, it's a growing, breathing, adapting thing, like a life form in itself...

Oh, and I aint no guru, I just heard about it a lot earlier than than most others and I've had more years to study, experiment, document etc... Now with this group going as it is, you can learn more in a few months than what it I've learnt in 8 years of doing AP... Well, almost...

Hex, I think I understand sort of what your getting at... Ultimately it's a bit like the style of a net pot suspended in an nft channel, with water dripping in from the top, except that your netcup is a continuous long piece of shade cloth..

Yes but is fun to tease on the odd occasion

Hi Stuart
I like "different", even better if its cheap and easy to do.

EB,
I think it`s similar to a dutch pot system, only it`s a trough
Something like this: http://www.nurl.us/6qm

Every plant could have 5 gallons of hydroton or more available.

It lends itself to narrow bed widths, the hydroton could be 18" deep even if the bed itself is only a foot or so wide, simply by making the loops longer. Even coverage will perhaps dictate the maximum width.

Most of the vertical systems seem to use this sort of trickle flow method.
The bonus with the trough idea vs a tower/tube is the roots have almost unlimited space to grow in (both downwards or sideways) and the plants all get an even share of the top and bottom water.