Backyard Aquaponics
A place to discuss aquaponics

Does anyone know where to get food safe floating rafts for AP ?

I am currently using polystyrene but I am not totally convinced it is food safe (?). I figured it may be once it has a nice slime layer on it.

PS: Dufflight asked this also in his thread, thought I'd ask it here too !!

As far as I know polystyrene is safe, they use if for food packaging like broccoli boxes.

I've been toying with the idea of PVC frame with a cover that the pots sit in. If it can't float enough then I can put a couple of containers under it to help it float. Like a raft. The main reason for my system is to block out some of the light. The secondary reason is for some of the water loving plants. Watercress etc.

I'm using a bread crate for the water cress. I don't know how long it will float if the fish let the cress get bigger.

Fill poly bags with 2 part foam for bouyancy, 1 cubic foot will support about 25KG

Milk or water jugs make good floats and they are food safe containers.

I have read questioning about the use of polystyrene ,, some proport? that the vegie roots can absorb some chemical from it?
I guess if you use those little mesh plastic baskets ,, just make sure it is solid where it goes through the poly.
I have not read any confirmed solid evidence that poly is dangerous ,, but if we only need to keep the roots out of it , then why take the risk.

it isn't just the plant roots that could take on undesirable substances, the water that the rafts float in could be tainted. That said, much of our food is packaged in or on several types of foam. Extruded styrene, polystyrene, etc. How safe is it really? I don't know but millions of people drink coffee out of foam cups every morning. I'm not even entirely certain how to find out how safe different materials are. I've seen some big systems using the pink or the blue foam insulation sheets like from the building supply yard. How safe it is I don't know but their fish are doing just fine with it.

i think that part of the concern with polystyrene is that generally the stuff thats large enough to use as floating rafts comes from the building industry and has a fire retardant incorporated (most times)

viewtopic.php?f=8&t=156&hilit=retardant

Hey thanks guys, great thoughts !

I'll try to mix a PCV frame with plastic milk/water containers. See if I can get the buggers to float with the weight of the plants.

Ideally I'd like separate modules so I can add or take away as needed. I want to cover most of the water from the sun. At the moment my water is really, and I mean *really*, greeeeeeeeeen.

make that PVC ..

Mine went green. Then cleared up. Then when green again. Now its starting to clear again. I think I'm seeing a pattern. Hope the silvers will help once they get here.

Has anybody used pumice for flotation? Do you know if it eventualy sinks and/or how long it stays afloat for?

Question is would you get any in a useful shape. Might be easier to look into plastic. pumice might contain elements that could dissolve and allow it to sink.

I suspect that pumice will eventually get waterlogged and sink. I know my lava rocks will often float when first put in water but will sink after a day or two.