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!)

 

 

 

[Vlad Jovanovic]

Most all of your food packaging is made from polystyrene...and has been for years. It's chemically inert and not known to leech (to the best of my knowledge) unless burned/heated/melted. It is a very stable (chemically) material (which makes it good for AP, but very bad for landfills as it doesn't really bio-degrade).

There are AP systems that have been certified Organic that use polystyrene floating rafts. 

It's about as apt to "leach" chemicals as your rigid PVC pipes (meaning it's not).

If you are still worried or otherwise philosophically opposed to using materials that come from the petrochemical industry, or (some would say "evil") corporations like Dow Chemical...start growing lots and lots of bamboo and reeds to use as floating rafts. Seriously, it would be a cool thing to see someone actually do.

[Josie]

Thanks Vlad,

I am not philosophically opposed to using it (but would be happy if something better came along). My concerns were raised by articles I have come across where they claim styrene is really bad stuff and that iit is more likely to leech if used to hold content which is high in fat or content which is hot. It didn't specify whether hot was anywhere above room temperature or somewhere significantly above room temperature.

I realise polystrene cups are used for drinks such as hot cofee but just because it is used doesn't mean it's a good idea. Also, in raft aquaponics the polystrene isn't just used briefly for one drink and thrown away, it sits in warm water for months and then gets re-used over and over again. 

Sounds promising that there are already AP systems + Polystyrene floats with organic status....... thanks for the info.

 
Vlad Jovanovic said:

Most all of your food packaging is made from polystyrene...and has been for years. It's chemically inert and not known to leech (to the best of my knowledge) unless burned/heated/melted. It is a very stable (chemically) material (which makes it good for AP, but very bad for landfills as it doesn't really bio-degrade).

There are AP systems that have been certified Organic that use polystyrene floating rafts. 

It's about as apt to "leach" chemicals as your rigid PVC pipes (meaning it's not).

If you are still worried or otherwise philosophically opposed to using materials that come from the petrochemical industry, or (some would say "evil") corporations like Dow Chemical...start growing lots and lots of bamboo and reeds to use as floating rafts. Seriously, it would be a cool thing to see someone actually do.

[Vlad Jovanovic]

I think many, many of us would be happy if something better yet still convenient came along. I'm not exactly happy about using it either (but not so much because of fear of leaching). 

Polystyrene is used for much more than the cups. All those "plastic" pudding or yogurt containers are actually polystyrene (just not the expanded or extruded variety), plastic knives, forks etc... polystyrene...

The "fat" thing probably has something to do with the fact that polystyrene is soluble in just about most organic solvents known to man. So, many oils and fats (non-polar) will dissolve the stuff, but others wont, (polar liquids).

Polar liquids like the hydroxyl group...alcohol, glyserine etc.. wont do a thing, but pretty much any non-polar liquid like fats or acetone will turn polystyrene to mush or worse, releasing toxic styrene. Time and temperature probably plays a significant role too (as with most things) in the solvent reaction. 

I guess keep the fish skinny and don't fillet them on the rafts ;)

Drinking hot coffee is probably 'ok' but squeezing a lemon into hot tea (in a polystyrene cup) might very well release some un-intended oil from the lemon peel which would surely react with the cup. This might be a minute reaction, but still highly undesirable IMO.

Josie said:

Thanks Vlad,

I am not philosophically opposed to using it (but would be happy if something better came along). My concerns were raised by articles I have come across where they claim styrene is really bad stuff and that iit is more likely to leech if used to hold content which is high in fat or content which is hot. It didn't specify whether hot was anywhere above room temperature or somewhere significantly above room temperature.

I realise polystrene cups are used for drinks such as hot cofee but just because it is used doesn't mean it's a good idea. Also, in raft aquaponics the polystrene isn't just used briefly for one drink and thrown away, it sits in warm water for months and then gets re-used over and over again. 

Sounds promising that there are already AP systems + Polystyrene floats with organic status....... thanks for the info.

 
Vlad Jovanovic said:

Most all of your food packaging is made from polystyrene...and has been for years. It's chemically inert and not known to leech (to the best of my knowledge) unless burned/heated/melted. It is a very stable (chemically) material (which makes it good for AP, but very bad for landfills as it doesn't really bio-degrade).

There are AP systems that have been certified Organic that use polystyrene floating rafts. 

It's about as apt to "leach" chemicals as your rigid PVC pipes (meaning it's not).

If you are still worried or otherwise philosophically opposed to using materials that come from the petrochemical industry, or (some would say "evil") corporations like Dow Chemical...start growing lots and lots of bamboo and reeds to use as floating rafts. Seriously, it would be a cool thing to see someone actually do.

[Josie]

 Sounds like a plan!   lol.

 
Vlad Jovanovic said:

I think many, many of us would be happy if something better yet still convenient came along. I'm not exactly happy about using it either (but not so much because of fear of leaching). 

Polystyrene is used for much more than the cups. All those "plastic" pudding or yogurt containers are actually polystyrene (just not the expanded or extruded variety), plastic knives, forks etc... polystyrene...

The "fat" thing probably has something to do with the fact that polystyrene is soluble in just about most organic solvents known to man. So, many oils and fats (non-polar) will dissolve the stuff, but others wont, (polar liquids).

Polar liquids like the hydroxyl group...alcohol, glyserine etc.. wont do a thing, but pretty much any non-polar liquid like fats or acetone will turn polystyrene to mush or worse.

I guess keep the fish skinny and don't fillet them on the rafts

Josie said:

Thanks Vlad,

I am not philosophically opposed to using it (but would be happy if something better came along). My concerns were raised by articles I have come across where they claim styrene is really bad stuff and that iit is more likely to leech if used to hold content which is high in fat or content which is hot. It didn't specify whether hot was anywhere above room temperature or somewhere significantly above room temperature.

I realise polystrene cups are used for drinks such as hot cofee but just because it is used doesn't mean it's a good idea. Also, in raft aquaponics the polystrene isn't just used briefly for one drink and thrown away, it sits in warm water for months and then gets re-used over and over again. 

Sounds promising that there are already AP systems + Polystyrene floats with organic status....... thanks for the info.

 
Vlad Jovanovic said:

Most all of your food packaging is made from polystyrene...and has been for years. It's chemically inert and not known to leech (to the best of my knowledge) unless burned/heated/melted. It is a very stable (chemically) material (which makes it good for AP, but very bad for landfills as it doesn't really bio-degrade).

There are AP systems that have been certified Organic that use polystyrene floating rafts. 

It's about as apt to "leach" chemicals as your rigid PVC pipes (meaning it's not).

If you are still worried or otherwise philosophically opposed to using materials that come from the petrochemical industry, or (some would say "evil") corporations like Dow Chemical...start growing lots and lots of bamboo and reeds to use as floating rafts. Seriously, it would be a cool thing to see someone actually do.

[TCLynx]

Friendly aquaponics got the organic certification doing raft aquaponics using Dow Blue Board (important point that it is the dow blue board and not the pink stuff I guess)

Biggest problem with the polystyrene is it won't last long out in the sun!  UV degrades it to a dusty substance that I don't like to handle.  So one then needs to figure out a safe paint to use on the top surface (but don't use it on the sides or bottoms).

[Josie]

More good info.Thanks. Really glad I joined this community.
 
TCLynx said:

Friendly aquaponics got the organic certification doing raft aquaponics using Dow Blue Board (important point that it is the dow blue board and not the pink stuff I guess)

Biggest problem with the polystyrene is it won't last long out in the sun!  UV degrades it to a dusty substance that I don't like to handle.  So one then needs to figure out a safe paint to use on the top surface (but don't use it on the sides or bottoms).

[Vlad Jovanovic]

I think Freindly's uses a water based latex paint for the tops of their rafts...(as crazy as it may sound to all you folks) I have finally managed to source (special order of course) an exterior latex paint for my rafts...Yippeee. (They're real big on oil based paints and nitro based paints here...Latex paints are very, very new here).

[Kaspars]

So, if my hydroton rises PH everyday i have to remove it and go for polystirene. Good solution! Will experiment with...

[TCLynx]

kaspars, I don't think hydroton is raising your pH unless it isn't really hydroton.  More likely you have hard water which is raising your pH or some other calcium carbonate material raising the pH of your system, either that or an anaerobic situation doing it to you.

Switching to Rafts won't necessarily fix a pH issue unless it involves removing limestone from your system.

[Vlad Jovanovic]

Hydroton should be relatively inert and should not be affecting your pH much if at all...Are you certain that it is the hydroton? If so, how?

Like TC says, maybe carbonate alkalinity in your top up water or algae causing pH swings even... (anaerobic zones seem unlikely as Kaspars is still cycling and probably hasn't had any long term development of root-bound plants yet...

[claude saunders]

Just went to an aquaponics workshop at Chicago State University last weekend. Myles Harston (original creator and owner of AquaRanch) is working on a new design for DWC rafts that I expect will go on sale some day. The idea being that they are organic compatible. Don't know much beyond that, but I think there are industrious people working to invent better rafts.

[Miles Perryman]

What thickness is most common in DWC raft system? 2" ? and how do I get the Blue Board, Lowes and HD dont carry over 1" thickness.