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Rafting lettuce

Discussion in 'New Aquaponics systems - off-the-shelf ready to go' started by dakine2448, Feb 1, 2013.

  1. dakine2448

    dakine2448 Member

    Sep 5, 2012
    I'm just getting ready to install a lettuce raft system in my 20' diameter tank. I'm using 1 1/2" styrofoam. [4' x 4'] 2" web pots. One side of the styrofoam is covered with aluminum foil and the other side doesn't have any cover at all. Does it matter which side goes up??
    Shiney or not?
    Advanced thanks
    Also what centers should the pots be? 8" apart??? or what. Holes right alongside the edge 6,7,8 inches apart??? Styrofoam sheets are 4 foot by 8 feet.
  2. Jeff.H

    Jeff.H Guest

    Jack, mate i have exactly Zero experience with raft, but can you explain the use of aluminum foil for me?

    Whats the idea behind that? Thanks
  3. Rob

    Rob Super Moderator

    Jan 3, 2010
    Yeah i haven't heard of using aluminium foil for anything either.

    I made my holes about 20cm apart fitted in a hex pattern, as i figured i could always leave some holes with nothing in them if i needed more space.

  4. Trewarin

    Trewarin Member

    Aug 1, 2012
    I'd recommend shiny up, it will reflect more light onto the undersides of the leaves of the lettuce... and prevent the foil coming off in the water.
    The foil is good, helps prevent extra UV getting into the GB.
  5. dakine2448

    dakine2448 Member

    Sep 5, 2012
    Thanks Trewarin,
    Not much info online on rafting especially in the same tank with the fish. I'm netting off 1/2 the tank to segregate the fish from the rafts. I'm afraid the tilapia will eat the roots. Someone said it's best to paint the styrofoam to help prevent it breaking down. Don't know abut that one.
    View attachment 14744
  6. Damon Polta

    Damon Polta Member

    Jan 26, 2012
    you might want to be careful using the rafts with the aluminum siding... the adhesive that adheres it to the foam board might be toxic... might want to check into that... it might be heat sealed to it... but better safe than sorry.

    also, you might want to look into the "slit" pots instead of the "web" pots... the webs are like a cross hatch, and when the roots grown out from the web pot the small holes make it hard to get the roots and plus (left over coir and lettuce stump) out of the web pot... i've found that its much easier to clean out the slit pots than the web pots to be able to reuse them... then again... we were changing out hundreds of these things a week... if i was only doing a dozen or so a month i dont think there would be much of an issue... but in the interest of time management... slit pots are just easier and quicker to clean out for reuse.

    also... on the slip pots, the rim have this 2mm ledge, which allows them to hang perfectly in the raft's holes... some of the web pots that i have used had a very little rim, if it had on at all... after you use the rafts a couple dozen times you'll experience some wear and tear... this is to be expected... what you'll find is over time the holes slowly get wider and wider because of the roots of the plants... so if the net pots have a tiny rim, you'll be finding you net pots in the bottom of your trough or tanks instead of hanging onto the rafts...

    also... you're going to want to find a way to keep the fish away from the plant roots... they'll eat them. flat out. you could try to build a frame around each raft, and put fish net around it to keep the roots in and the fish out... kind of like a root basket... even if this is done, your plants closest to the edged will suffer some damage because the fish will attack the roots through the netting... the best thing to do would be to either plum the water into a trough system, or to find any other way to separate the fish from the roots.

    during production, if the lettuce was growing too quickly and throned to upset the logistics of the farm, we'd throw a few medium sized tilapia into the troughs to eat the lettuce roots. this would slow down the growth of the lettuce and wouldnt kill the lettuce too quickly... it would give us about a week long buffer to allow us to catch up the harvesting cycle with the rate at which the lettuce grew... we ran the logistics on averages... so when we'd hit a week with exceptionally good weather... we were growing more than we could sell... after we hit the area that was growing too quickly, we'd just net up the fish we put into the troughs and then replant as normal.

    as simply fix for this would be to wrap a rubber band around the top of the web pot to increase the rim diameter to allow for it to better hang in the hole... or, another solution would to be just to find the slit pot that have a larger rim...
    Last edited: Feb 11, 2013
  7. dakine2448

    dakine2448 Member

    Sep 5, 2012
    Thanks for the GOOD info you guys. I'm going to try and put a shade clothe "fence" dividing the tank into. Then put the rafts on one side and the tilapia on the other. That's plan number 1. It would allow for better aeration. I can box off individual rafts with shade cloth also. Hard to attach it to the foam tho and when algae grows on it there will be little aeration.
    Fence off seems the better so far.
    Aloha Jack
  8. Tracy Holz

    Tracy Holz Member

    Mar 23, 2013
    Also if it was used to shine underneath that would direct more light & almost certain to get some in the water - & you all know our little friend Algae.....
  9. pioneer07

    pioneer07 New Member

    Feb 4, 2014
    Hi there, I am right now endeavoring to develop "Green Deer Tongue" lettuce in a pontoon under several high yield T5's developing utilizing Pure Blend Vegetative supplement result. This is my first endeavor at developing anything since i developed beans in wet napkins in kindergarten. LOL
  10. columnmn

    columnmn Member

    Nov 10, 2012
    Hi Pioneer.

    I just had to do a little research on green deer tongue lettuce. Looks nice.

    You aren't combining hydro and Aquaponics are you? I don't think the fishies will like the chemicals too much.

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