Backyard Aquaponics
A place to discuss aquaponics

If you have a raft system do you have a couple growbeds with gravel to filter before heading to the raft beds? I have been planning on just gravel beds, but I think I can build raft beds and still be able to move them around if I need to. My big question is about plant varieties. Can I grow anything but lettuce in a raft? Can you do beans, peas and tomatoes?

Any input on raft experience would be great. I think we have our greenhouse nailed down. It is going to be 14' x 32'--so that is what I have to work with.



Thanks!!

You can grow anything IF you provide supports if the nutrients are there. I grew rock melons in deep water culture. You just have to decide what is most practical to you.

Any chance you could post some pics of your DWC system DanD

not sure if this is the raft system you are refering to.

and smaller raft

I dont want to post a pic of my system after seeing the one pea shoot posted, lol. Mine was just a 50 gallon rubber made tote using net pots filled with expanded clay balls.



Now you have to scan the picture and find the rock melon

The bottles around the edge were a 2 liter coke bottle flood and drain system (EEB). The tote is buried in sand to keep it cool. I grew rock melons in both the EEB and DWC. Everything in the DWC did better; grew faster, larger and produced more. I did have an air stone under each plant though. In the pic the eeb rock mellon plant fall over the side to the ground and the DWC rock mellon vine falls over the top of the wire cage with a melon hanging in the air. It grew just fine hanging like that.

Oh, Its one of them white 2 eyed melons

The problem with rafts in AP is you need a seperate tank - you cant just chuck them in with the fish = no roots

I'm in charge of getting the feed-our-family-of-six-aquaponics plan worked out. DH is building the greenhouse and beds. I was looking at aquaponics.com and they recommended the raft system as the easiest for newbies. They only sell NFT and RAFT kits. So I was wondering, why? I can see the benefit as it would be easier to drain a bed to clean it and/or move it. If I can grow anything in it then maybe it would be easier. I was thinking scattering seeds on gravel was the easiest way to go.

I am willing to bag the whole raft idea, but after reading you can do 4:1 , rafts to tank volume I am now confused--again--this is getting to be a theme with me.

Aquamama, many of the first AP systems utilised floating raft systems... ala UVI, S & S Aqua Farms..... and here in Australia Wilson Lennard undertook a Phd study using the technology....

Many "commercial" system are based on floating rafts... including the one pictured... "Red Heeler Aquaponics" ... picture from one of the links on their website....

http://redheeler.aquaponics-shop.com/our-system.shtml

Here's a members thread, with pictures... hope you don't mind Alchemist

viewtopic.php?f=18&t=2753&start=0&st=0&sk=t&sd=a&hilit=alchemist

And TCLynx has constructed lined growbed which could be used for floating raft... although hers are deeper, you get the idea...

I am like you Aquamama with respect to which type of growbeds. So many possibilities.

I am just gonna try what is simplest and cheapest to start with. If that doesn't work, then plan B.

Oh yea, I haven't figured out what is simplest and cheapest yet.

I did find out I can get 3/8 inch pea gravel for $22 dollars a ton from the local concrete place.

I'm so glad I am not alone. I really appreciate all the pics. I have " THE aquaponics binder" that is hundreds of pages thick now. I'm going to print off all these links and pics. Thank you.

To throw a curve ball at you another "grow bed" option could be vertical planted walls, although these are more experimental/not often seen. Towers are another way to add more plants too (strawberries).

I ran a very small trial of lettuce in the same system using a gravel grow bed and rafts. In my system, the gravel grow bed won hands down. The plants grew much more quickly, were darker green and much more robust.

I had the floating plants just floating and did not use airstones beneath them. Not sure if that had anything to do with the results.

I expect that in DWC the extra air stones under the plants makes a big difference. (I know it does in Hydroponic culture.) If that experiment were to be repeated with one set in DWC without the air stones and another with air stones, the ones with air stones would probably be as good as the ones in Gravel.

Something to take into account when choosing method, there needs to be some sort of media somewhere in the system. Most of us do gravel grow beds as the simplest method of getting support for plants while at the same time providing surface area for bacteria and solids filtering all in one container.

The NFT, DWC, vertical etc, other methods all will require some form of bio-filter and solids filtering.

If one wants just a few small floating rafts over the fish tank, the roots could be protected in mesh baskets so that the fish can only eat the ones that grow beyond the basket. I would make sure any plants done this way are not going to be bad for your type of fish.