Polystyrene floats in DWC

[Josie]

I love Aquaponics but have yet to start my own set up. I'm still trying to fill in my knowledge gaps.

I am concerned about Styrene leaching into food from Polystyrene floats used in DWC, Anyone know anything that will stop me being concerned? Everyone seems to think it's only a matter of time before Aquaponically grown food is classed as organic but this will not be the case for DWC using Polystyrene floats.

Hope someone Knows more than me (should be easy!)

 

 

 

[Bart]

Awesome thread folks, thanks for doing all the heavy lifting on this, I wasn't even sure where to start looking for this kind of information.

 

 

[David]

No problem bartman. Vlad and TC are huge resources in their own rights. Im more of a tweaker who tests the limits and questions everything and not too proud to admit when I screw up.

[TCLynx]

TC isn't an authority on rafts though by any means.  I seem to keep turning my raft beds into water plant growing spaces instead of using them for rafts.

[Vlad Jovanovic]

I on the other hand am not an authority on anything...except maybe NDT/forensic engineering and Delta blues...

[TCLynx]

I don't know Vlad, sounds like you have gained quite a lot of good experience for indoor growing in your cold winter climate.

[Vlad Jovanovic]

I may have picked up a thing or two...Now if I could just remember which pocket I put them in...

[TCLynx]

I know the feeling..... wait easy to tell with aquaponics, the pocket would be wet.  Well of course if you just took a fish water shower you are all wet so again hard to tell which pocket.

[David]

I forgot to mention they are also very modest. TC I like the water table garden ideas!

[David]

After drilling 42 holes by hand for two of the four rafts....Im beginning to entertain the idea of a water lilly pond on bricks....

[Glenn Davis]

I'm very glad I found and read this thread. I bought insulfoam to insulate my fish tank and decided to use a piece for my DWC raft system. I'm gonna change that after reading this, so is DOW blue board is the foam of choice for raft systems? If the fish tank is just sitting on the insulfoam that should be alright correct?

[David]

Yes and yes.

[Vlad Jovanovic]

Ok, since it turns out that I can't buy anything called 'Exterior Latex' paint in this country, and want the expansion/contraction flexibility of exterior latex paint, but can do without the sloughing quality I did some snooping...

It turns out that there is absolutely NO LATEX in "Latex Paints"...and hasn't been for many, many years...(no big surprises there)...

What is interesting though is that the cheap "latex" paints use vinyl resins, while the more expensive "latex paints" uses acrylic resins. This may be why nobody here has ever heard of "Exterior Latex Paint"...because it's called "Acrylic Exterior Paint"

All "Latex Paints" use synthetic polymers such as acrylic, vinyl acrylic (PVA), or styrene acrylic, as binders. Before I realized this, there was much confusion in my head...i.e "is acrylic water based paint safe for AP?...can I mix the interior latex paint that is available here with the exterior acrylic paint that is available here, or will it seperate"? blablabla..."

1 litre of int. latex paint will cover 7-9 m2,  in two coats but will in all likely-hood crack and peel in the GH because it is pretty rigid and will be exposed to wild temperature swings ... whereas

1 litre of ext. acrylic paint will only cover 3-4 m2...is very nice and flexible BUT costs more than double...and if you have almost 100 rafts to paint, that's pretty pricey...SO...

I'm just gonna mix the two together in some ratio and basically going to be using the expensive ext.acrylic paint as an additive to the cheaper int.latex paint for better elastomeric properties...Which should give me something more along the lines of what you all, in the Land of Milk, Honey and Home Depot, call a decent quality exterior latex paint. (Or depending on my mixing ratio a good quality int/ext latex paint)...

The interior latex paint I can get uses styreneacrylate dispersion, while the exterior acrylic paint uses a styrene–acrylic copolimer. I imagine these should blend well together...

At any rate, hope this may be of some use to someone, somewhere...(like if you don't live in the US and are trying to follow a manual written there)...

Jon Parr said:

Vlad, you may be better off with interior paint, rather than exterior. I know that advice is counterintuitive, but exterior paint is formulated to slough off. Since the sun fades all things, the paint is designed to be slowly eroded by the elements to expose 'new' paint, thereby remaining more colorfast, and shedding moss, algae, mildew, spider webs, etc. That is why old houses are a little chalky when you touch them. Interior paint, on the otherhand, is not as colorfast but is designed to resist the elements so that it does not powder off. Interior/experior paints are probably the best, being both uv resistant and non-sloughing. My $.02