Use a Lettuce Raft hydroponics system?

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Smilesbetter
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Use a Lettuce Raft hydroponics system?

Post: # 281113Post Smilesbetter
Tue Aug 19, 2014 9:34 pm

Hello!

I am looking to start one or two small indoor lettuce raft hydroponics systems within a month or so and am hoping to grow a few different types of lettuce in it, as well as possibly pak choi and some herbs. I think it should be fairly easy to set up, but I have a few questions regarding the actual operation of the thing:

1) is it okay to grow all these types of plants in the same system, or should they be split up? What sort of pot sizes do they need, is bigger better or will they grow fine even in a tiny pot?

2) what type of nutrients am I meant to add to the water? Is it actually eco-friendly to do this and is there a risk of adding bad chemicals too?

3) I understand that after harvesting, the plant regrow. Is there a certain amount of times I can do this or will if continue to regrow forever if I let it? And how do I harvest seeds from these plants? Do I need to?

4) how do I actually bring up the seedling from seed without soil? I can't find any dummy's guides for this haha.

5) I hear LED lighting is "controversial" haha but I can't find out what exactly is meant by that, is there something wrong with using LED? Is there a more eco-friendly but safe light? And what makes a good LED light for a grow light? I've really not got the first clue.

6) what kind of thing is best to use instead of soil, that is also eco-friendly and reusable? A lot of the things I've seen can only be used once. Do I need to replace this soil-equivalent a lot? How do I know it needs replacing? When I replace it, can the plant be put into the next stuff and continue growing, or is it best to get rid of the full plant and start anew in this situation?

Haha sorry for all the questions, and I hope this is the right place to post! I am a complete beginner and actually only came across hydroponics (actually aquaponics,but this seems like a good place to start) about three days ago, but ever since I have been fascinated and desperate to get started in some way!

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Re: Use a Lettuce Raft hydroponics system?

Post: # 281117Post ojay54
Wed Aug 20, 2014 6:02 am

Tony 'll be along soon ........

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MKG
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Re: Use a Lettuce Raft hydroponics system?

Post: # 281118Post MKG
Wed Aug 20, 2014 6:23 am

Nah - he'll be very late and then three Tony's will turn up at once. Or is that something else?
The secret of life is to aim below the head (With thanks to MMM)

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Re: Use a Lettuce Raft hydroponics system?

Post: # 281130Post Odsox
Wed Aug 20, 2014 8:51 am

Three ?? Good Lord is there room for three Tonys ? :shock:

Yes, I did experiment with raft hydroponics a few years ago, and it worked very well, in fact I may well start doing it again as it's an ideal way to grow indoors and during the winter too.

So to answer your questions, (1) you can grow anything that will grow hydroponically. I know that's not really an answer, but trial and error is one way to find out and another way is to see what commercial growers are growing. Lettuce is easy to grow and I would imagine Pak Choi would be ideal too but not so sure about herbs, that would depend on which herbs you want to grow. Mint most certainly would grow well as it's a water loving plant to start with. If you use "universal" nutrient then any combination can be grown together.
In my raft system I had a sheet of polystyrene with holes cut to suit vending machine coffee cups, the lettuce was then planted in those cups and produced full sized plants.

(2) I would buy ready made nutrient, at least to start with, you don't want too many variables on you first attempt. They are of course 100% inorganic. I run two other hydroponic systems full time and I'm about to experiment with nutrient made with an activated tea of comfrey, nettles, sea weed and peat, but probably not that easy to do in Berlin.

(3) Sorry, can't help there, I replace with new plants when I cut a mature lettuce.

(4) I sow seeds in 2" pots and when they are big enough I wash the compost off the roots and transplant into the coffee cups. The cups have several large holes made with a hot soldering iron, then lined with muslin and filled with vermiculite. The roots then grow through into the nutrient.

(5) Nothing wrong with LED lighting, in fact it would be essential for indoor growing, especially in winter. There are other lights that are cheaper to buy, CFLs and ordinary florescent tubes, the sort they sell for aquariums work well. Just look for tubes marked "growlux" or similar.

(6) I use a mixture of vermiculite and pearlite in my main hydro system, but on the raft I used pure vermiculite as it's heavier and supports the plants better (stops them toppling over when they get top heavy) Vermiculite can be reused for ever, just wash it in a fungicide if it's gone green.

You will need to oxygenate the nutrient continuously as the roots need oxygen, get an aerator from an aquarium shop, the sort with an airstone, they cost very little to run. If you intend to grow during the winter in an unheated room, then I would also get a small aquarium heater. Keeping the nutrient at about 20c will suit the plants nicely regardless of the air temperature (as long as it's above freezing)

I cut a piece of expanded polystyrene to almost fit the tank so that it allowed the raft to rise and fall with the water level, but with a smallest gap possible to keep the nutrient in the dark to stop algae growing.

Hope that helps, anything I missed or you don't understand just ask. It's a great fun thing to do and you get something to eat at the end.
Tony

Disclaimer: I almost certainly haven't a clue what I'm talking about.

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Re: Use a Lettuce Raft hydroponics system?

Post: # 281152Post Smilesbetter
Wed Aug 20, 2014 12:00 pm

Hello, thanks so much for the informative reply! I intend on growing lettuce (Although I don't actually know much about individual lettuce types haha), chives, basil, mint, pak choi, broccoli... Mostly different types of lettuce though I think. i read that some plants drain the water quicker, but i suppose that doesn't matter too much on a raft system.

Thats a great idea with the coffee cups, I should be able to get those fairly easily here. I assume you mean the plastic ones? Are they not too flimsy?

Thanks, would love to hear how you get on with your activated tea. Thanks so much for all this information! I'm hoping to start getting all the stuff ready and start growing the seedlings this month, to get started as soon as possible. I'm already making a space in the kitchen for the system (No cats allowed, one is quite fond of eating my plants). I'd never actually though about having to heat the water! I should be able to get a water heater when I get the pump and things. I have been directed to a local weed shop that sells all sorts to do with hydroponics (Ha ha, never thought I'd be shopping there!) to get the various parts I need and hopefully also the vermiculite.

So excited to get started with this project!! I'm sure though I'll be here with many questions for you as I'm first getting it set up haha :P

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