Foam

[Chris Smith]

There are several choices when it comes to foam. I prefer to use Dow blue board. This is an extruded form of polystyrene. This means that the entire board is made of one continuous piece of foam. This foam of very durable and will last many years. Blue board comes in several forms and it is important to get the right one. The best is "square edge" and not the "score board". Square edge foam is a solid sheet of foam. The score board has scores top and bottom to make it easy to break. The scores are at a standard stud layout and intended for insulation in walls. The scores make it easy for contractors to break and install.

The other type of foam is EPS or expanded polystyrene which is thousands of small pellets that are expanded into a form. The EPS foam is not nearly as strong as extruded and will break down easily. Roots of aggressive plants will actually grow into the foam. I have one of these sheets in my system and it is now dedicated to mint as the roots are growing throughout the foam.

[Joe Bifano]

The product was http://www.insulation4less.com/Insulation4lessProduct-1-Prodex-Tota....  They are having a sale right now.

[Paul Trudeau]

thanks Joe for the quick and informative reply!

Joe Bifano said:

The product was http://www.insulation4less.com/Insulation4lessProduct-1-Prodex-Tota....  They are having a sale right now.

[Joe Bifano]

This stuff works fantastic.  I am using it for all kinds of things.

[Dave Love]

Hi Josh, 

I agree, it is troubling to see brominated or other halogenated flame retardants on the MSDS ingredients list for Dow blueboard.  Basically any construction-grade rigid foam polystyrene sheet insulation will have flame retardants, which is problematic-- if they leach they can be harmful to animals and humans 

http://en.wikipedia.org/wiki/Brominated_flame_retardant

extruded styrafoam may not have this same issue, but it is good to ask the manufacturer for the MSDS

Josh Fagan said:

Hey all, just joined group!

I don't intend to come off as ignorant, but all the foam mentioned will leach into both the water and plants, right? What am I missing?

Has anyone tried a wooden raft? Are there no other options out there besides foam products?

 

Thanks!

[Siggy G]

I have no experience with aquaponics yet, but after reading a bit on this site I feel I have a general understanding. I have a couple thoughts/questions.

Seems like the foam boards would have to be handled delicately in order not to damage them. Is there any company selling something especially for DWC aquaponics. If not, it seems to me that there might be an untapped market for someone to manufacture something more durable. I have a background in manufacturing from before I changed over to agriculture a couple years ago. It seems as if a floating net basket would be a better solution than the rafts. I figure a net basket that had a hollow or foam filled ring around the outside would do the trick. HDPE baskets would eliminate the potential  issues with leaching anything into the water and are far more durable than the foam. They could be designed so that they stack inside each other to reduce storage space required and also reduce shipping costs. It just seems to me that people are spending a lot of time and energy making these rafts and they aren't quite satisfied with what they end up with. With floating baskets you could also accommodate different size baskets in the same area for different crops.

[Harold Sukhbir]

Hi Siggy,

I too have long thought about this. Foam boards also limit our troughs to fixed sizes by virtue of the available 4 x 8 sheet. In most commercial operations the boards are cut in 2" H x 4" W, to allow ease when harvesting/planting. I conceptualized a square HDPE injected form complete with central 2" and 3" net pots produced in one piece. The square ring would be a dimension which would provide varied plant spacing required. It would have to be sufficiently buoyant to keep a variety of plants afloat, of course. The operator would then be able to design trough sizes to his preference. Cost should be lessened as we have one purchase in a manufactured product as compared to the 2 items as we have now, namely net pots and foam. Also there will be a saving of labor in the drilling and cutting of sheets and there is the factor of the longevity of HDPE as you mentioned.

[Vlad Jovanovic]

Dave or Josh, could you please link a copy of the MSDS sheet you have from DOW, since the one I was have does not list HBCD or any brominated flame retardent as being used in DOW's formulation. Owen Corning, and Insulfoam, yes, but again DOW's specific MSDS for BluCore does not list any such thing. I also know of regional companies that do not use HBCD in their rigid foam products, so, as it stands I take issue (no offense) with your statement ..."Basically any construction-grade rigid foam polystyrene sheet insulation will have flame retardants"...

It may be that I was sent an old MSDS sheet or vice versa...or there is some other kind of 'mix-up' at play...which would be nice to resolve...

Thank you.

Dave Love said:

Hi Josh, 

I agree, it is troubling to see brominated or other halogenated flame retardants on the MSDS ingredients list for Dow blueboard.  Basically any construction-grade rigid foam polystyrene sheet insulation will have flame retardants, which is problematic-- if they leach they can be harmful to animals and humans 

http://en.wikipedia.org/wiki/Brominated_flame_retardant

extruded styrafoam may not have this same issue, but it is good to ask the manufacturer for the MSDS

Josh Fagan said:

Hey all, just joined group!

I don't intend to come off as ignorant, but all the foam mentioned will leach into both the water and plants, right? What am I missing?

Has anyone tried a wooden raft? Are there no other options out there besides foam products?

 

Thanks!

[Rob Nash]

I am sad to report... when i went to pick up my blue board, i had a conversation with the guy and he said all building products must have a flame retardant added... even the Dow Blue Board. He was very certain that they all use the same one. ...i mentioned the forum and all the to-do about the MSDS and how we were sure the blue was the safest etc. and he said "sorry, but the law says they have to add it to all construction materials" ..now this guy makes foam products, and mixes the chems and stuff at the factory, on site, hes not just a reseller.     Alamo Foam, San Antonio Tx

However, he did say that he doesn’t know of a single study that proves that it leaches out... but of course he didnt know if any of the studies were done in DWC ...or any food growing system.

ARRRR!!!  all of this while im loading the 20 sheets($800) on my trailer....

do we need to try wooden rafts? if so what type of wood could float for 30-45 days without getting saturated?... perhaps they would have to be rotated in and out of the system to allow them to dry.

[Siggy G]

I have my doubts that the foam leaches anything significant out after the initial couple days of contact to water. The DOW board is closed cell and water impervious. So only the chemicals at the surface have opportunity to leach into the water. If this is really a concern I would suggest a multi step cleaning after you have finished any cutting.

1. wash with dish soap.

2. Scrub down with a acidic solution that has a pH lower than you ever expect to experience in the system. Diluting vinegar or muratic acid to the right ph for example.

3 Scrub down with a caustic cleaner such as TSP.

4 rinse well.

Those steps should get the majority of any solubles off the surface.

Or find something that adheres well to it and doesn't leach anything out, coat it with that.

[Vlad Jovanovic]

Again, an MSDS sheet would be a huge help (if nothing else than to compare regional msds sheets)...It may be that here in the no man's land of south eastern europe, no such regulations exist for DOW or anyone else here (we are not part of the EU) and fire retardants are an added manufacturing expense...That may or may not be the difference.

As of yesterday when I tried to check, the links to the msds sheets and literature for the US market on DOW's site is down...DNS error blabla...

The Dow MSDS sheet I was sent some while ago had no such HBCD retardants listed. There are different msds sheets for different countries/regions...HBCD (hexabromocyclododecane) flame retardant is being banned globally (with the possible exception of the US of course)...Sure would be nice to know what is going on with that one...The plot thickens as some companies have voluntarily stopped using HBCD  as a flame retardant (as it is not the only retardant suitable, just the cheapest for industry) for certain markets. I know it's kinda weird but companies here have a bit of a track record for 'voluntarilly' taking such measures...Not because they're swell guys, but because people here here have a bit of a track record of mass boycotts and protesting...

Rob, polystyrene is pretty stable unless exposed to non-polar liquids or heat/flame...the HBCD is anyone's guess though...

There's a guy (professor I believe) named B.A. Kratky who came up with a growing system that's basically a pontoon DWC raft with an air space between the top of the water and the bottom of the raft (1996, Non-Circulating Hydroponic Methods, DPL Hawaii, Hilo, HI.)... and a guy named Giorgio on this site, also from Hawaii, who seems to have modified this design...http://community.theaquaponicsource.com/group/raftdeepwatercultureg... (maybe Giorgio came up with this independent of any knowledge of Kratky's system IDK) it might be worth looking into esp. if this HBCD thing in the US turns out to be a bust and you need a different raft material...There's also a swell company in Canada Beaver Plastics)  that makes rafts specifically for the purpose of growing food that might be worth checking out. I doubt they have reason to use flame retardants in that particular line of products, (they appear to make a range of products for a variety of intended uses) but you can always call/write to confirm (if Jon Parr hasn't already)... ...http://www.beaverplastics.com/productBrochures.html

Also, you may want to see with a small polystyrene factory (if such a place exists where you alive, I know they like everything BIG in TX hehe) to see if they'll produce a batch for you without any flame retardant (in the US this is apt to be the problematic HBCD..?  

[Rob Nash]

Vlad, I did locate a small manufacturer that does packaging inserts made from foam. ..they dont use retardants at all. we talked and he understood the needs and said he would get back to us with a quote. ...$18,000 just to make the mold. then a 10,000 minimum order, with the per unit costs for a 2'x4' was $40.  ...so it can be done, but just like everything in Tx... Go Big, or Go Home

[Rob Nash]

I think the bottom line is to do our own tests. There are plenty of us who have had rafts floating for more than 2 years... we need to find someone who can test the water to determine if its contaminated with these products. Any thoughts on what type of facility would do those types of tests? I would think as a consumer, there may be a government group that would do it for free. If so what should we ask them to look for?