April 4, 2009 by Peat
Posted in
Next , future project...
I'm feeling the urge to grow lettuce, more than the 7 pod system can supply.
The next conversion is for a 'raft' system, this comprises styrofoam (or similar) which floats on the surface of the water in a rubbermaid type container. In the foam you drill several holes and place net pots into them, probably 2". In the net pots go rockwool with lettuce seeds/herbs in, backfill with hydroton grow rocks for stability. Nutrients, as usual, will be the General Hydroponics Flora 3-part range.
I'll then use this to churn out decent quantities of lettuce/herbs, whatever. But only light plants, a tomato would sink my raft!
See THIS link for the full grow. 
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Mon, 04/06/2009 - 11:38
#2
Hi Peat,
Cool! I've seen
Hi Peat,
Cool! I've seen similar successful setups. What will your light source be?
Thanks,
Beth
Mon, 04/13/2009 - 03:48
#3
Stonecold - aquaponics, did
Stonecold - aquaponics, did not think of that one. 
Beth - I've got a 125w CFL 6400K lamp, currently in use on the DIY Aero System - pictures shortly...
Sat, 04/04/2009 - 14:56
#4
Fascinating!!! I want one!
Fascinating!!! I want one!
Sat, 04/04/2009 - 15:52
#5
Amazing film, I had no idea
Amazing film, I had no idea of the scale of this sort of production.
You remember my DIY Aeroponic project, well, it would be very simple to make a decent sized raft system. Take the same rubbermaid type container, cut some styrofoam to fit inside, but not too tight. Make your holes, pop net pots, rockwool and hydroton in and just 'float' the whole thing on the water. As the water goes down, so does the raft, the roots maintain contact at all times - the grow will be pretty good, you will get a decent crop of lettuce.
The AG was a thought, but I'm more tempted now to do it in the rubbermaid...
Sat, 04/04/2009 - 16:33
#6
Agreed, good film. I've seen
Agreed, good film. I've seen that kind of lettuce for sale around here. (Usually called Boston lettuce, I think.)
Definitely re the rubbermaid, Peat. Much better spatial flexibility. I do think you'd get much faster growth if you got some kind of airzone under them (aeroponic aot hydroponic growth rates). Like maybe 1" stryofoam stilts on the rafts, after the roots grow?
It's a pity one has to beware the algae. Would be so much easier if each lettuce got a mini raft to itself. So they could just space themselves as they grew wider...
Sat, 04/04/2009 - 17:11
#7
Yes, I think the rubbermaid
Yes, I think the rubbermaid will be far better - the poor 'ole AG's are getting rather battered now. Like the idea of the mini rafts, that would be so cool, floating around individually with the air bubbles moving them. 
It's a shame the algae has to spoil the party.
OK, I'll get this constructed then and put the details up on here as usual...
What's left to build now, NFT (Nutrient Film Technique) and Flood & Drain. 
Sun, 04/05/2009 - 17:50
#8
Aquaponics? :P
Aquaponics? :P
Sat, 04/04/2009 - 12:47
#9
Interesting, Peat.
Why do you
Interesting, Peat.
Why do you think this would support more lettuce than the 7 pod holes? I should think the plant roots would get less air this way, and not really add capacity? I'm told the primary way airstones oxygenate water is by their bubbles popping at the surface, and floating something on top would kinda frustrate that.
Should probably draw a distinction here between lettuce and brassica. Lettuce seems to have a surprisingly small root system. Brassica, not as small.
Sat, 04/04/2009 - 13:21
#10
The idea is to have more
The idea is to have more holes than seven, therefore more plants. No point in doing it with just seven holes, the AG does that good enough. 
The 'raft' technology is highly successful, and in frequent use to grow lettuce/brassica/herb type plants. In this instance I am not bursting bubbles onto the surface for the roots, they remain completely submerged. The air stone will still supply enough oxygen to the plants, it does not have to burst on the surface to benefit the roots - it won't effect the grow at all.
Check this site to see how this system is used for mass lettuce production.
Sat, 04/04/2009 - 14:51
#11
Thanks for that link Peat.
Thanks for that link Peat. Very informative.
This project is now over here where the first grow will be done.
I had no idea I'd left this so long before getting it done!