rafts for DWC

[Michelle Silva]

Can anyone advise what the difference is between using Dow blue boards and the white 2" styrofoam at Home Depot. Do the dow blue boards need to be painted? I don't know if I would ever try to be "Certified Organic" but I would want to do what is safest.. Does it make a difference? Thanks.

[Michelle Silva]

WOW! I just checked out that ecovative site..cool stuff, never heard of it. I'm going to call them tomorrow. It looks great, however, I do wonder about the costs..plus, they're in NY so not sure about shipping too.
Hmmm,not sure what poyurethane insulation is,will look into it...sounds like a lot of work and still sounds like chemicals, although guess it would be less messy.

[Florida Hydroponics]

Yeah, I didnt realize how big Dow was until I read your post and did a little research. I should have known...lol.. shame on me.

Have you heard of a new organic foam installation alternative made from mushroom spores? If this stuff floats, that would be awesome. Also, it seems like it would be perfect for micros to culture. If it biodegrades in the water though, that could be bad. Here is a company that makes it, but looks a little expensive: http://www.ecovativedesign.com/

Polyurethane insulation might be what you are looking for. It usually comes in a foam spray, but it shouldn't be too difficult to build a frame to mold the foam into boards.

What do you think?

[Michelle Silva]

Thanks for the all the info. Yes, pretty well known how bad sytrofoam is for the environment and I have had some trouble with the idea of it and of supporting Dow! I thought about using wood pallets..could get them for free too..but would be afraid of ripping liner and absorbing water.. Does anyone know if wood would absorb more water then the reg styrofoam boards.
There's been some posts on floating the rafts above water for aeration. I thought that it's desirable to have the rafts floating on the water because the underside of rafts act as a biofilter..if it's floating above then you don't get all the beneficials underneath.

[Florida Hydroponics]

Yeah, the white stuff really sucks. Its a pain to cut and leaves them styrofoam little circles all over the place. Also, your holes for your plants over time are easily worn and will become too big.

The blue Dow boards work very well. The think 2'' boards seem to hold up a lot better than the smaller 1'' ones.

The down side of Dow Blue boards is that they are made by Dow - is the world’s fifth largest chemical company, with annual global sales of more than US$20 billion. Dow manufactures and supplies more than
2,400 product families, including chemicals, plastics, energy, agricultural products and environmental services for customers in 164 countries around the world. Dow is also the world's largest manufacturer of extruded
polystyrene foam. (from the Dow website)

The Dow boards are made from Polystyrene, which is an aromatic polymer made from the aromatic monomer styrene, a liquid hydrocarbon that is commercially manufactured from petroleum by the chemical industry. Polystyrene is one of the most widely used kinds of plastic. (from wiki)

So pretty much, these Dow boards are not environmental friendly, but I dont know if that would exclude the crop from being organic. I did some searching and I couldnt find anything on organic installation boards, other than organic spray foam. Something that might work and all natural would be some wood boards that float, but thats just an idea I thought of.

[Giorgio]

Hmmm...Good question, I've been using the white EPS boards for almost a year and I'm expanding my system now and I want to find something different the white stuff absorbs too much water and it get brittle and breaks easily, the DOW BLUE is much better but also much more expensive and unfortunately I can't get it where I live unless I order from mainland, I know the roofing supply stores carry the DECKMATE OR ROOFMATE which is DOW foam same as blue and it might cheaper, again I can't get here in the island.
I just happen to find some other foam used for waterproofing here in my local roofing place and it says green foam ( I will do some research) its only 1/4 thick but: I have an idea.
I noticed those pool noodles and they are cheap, all my rafts are 2x4s and can attach the noodle under the foam to make higher and also to allow air to aerate the system.
the foam is cheaper than anything else so far, about $100 for 4 x 100'.
I will share with you as I progress