Backyard Aquaponics
A place to discuss aquaponics

I think aa brought this up before but no one answered what about polystrene boxes.

Yeh, i remember! We weere all deathly silent on it

Well its used as floating rafts quite a bit. I don't think its terribly UV stable and if you open up a fresh polystyrene box it smells quite a bit, but it is used for fruit and stuff too. Will do some web searching when i get a chance

Hi Creative,
The pond liners are different to the greenhouse covering. The pond liners do not have anything on them about weather they are food grade or not, but I will find out.
They would be a good way to make grow beds or fish tanks on the ground or in the ground. It would be a fairly low cost way to build a system. I will get back with info about the food rating or not.

Re Styrene boxes - I would not think they would last too long. I have used them in the past to grow seedlings in and they start to break down pretty fast out in the sun.

Muzza

I have had poly boxes recommended for white worm farming and little else since making enquiries. The worm farm is out of the sun...

I grew in a poly bed for 6 months no problems but it chips and gets in everything and was only for 6 months (first junk I scrounged). It was also under HPS lighting, nowhere near as potent as the sun.

Styrene boxes can last a bit longer if you give them a coat of paint or cover them so that uv etc cant react with them as quickly... areas which are covered with stickers dont break down to dust like the areas left uncovered

do you think that yabbies would claw through them

Not sure about clawing through, but i have had a yabbie or two escape from one, just by climbing up the sides of the polestyrene box

They are escape artists EXTREME. you basically have to have a completely smooth tank with nothing hanging in there like heaters and air lines or have the tank covered, i've lost about 5 from them climbing out, and when they are large they have extraordinary strength in their claws, they can lift small panes of glass up

I read somewhere of using natural latex painted on the polystyrene sheets to provide a natural barrier between plants and sheets in float (raft)systems

I will have them in my stainless vat, so there will be no escaping for mine, only exit will be via the net and bbq!

now that latex paint sounds like a viable option!

Stu, you just won't be able to get them to breed in there, you'll have babies growing out in your plant beds with that pump! even with a sceen.

Ahhh, i ain't pumping out of that tank. It is purely tidal. Have linked the 2 tanks via a conglomeration of fittings, now hoping that the ideas man will litterally help me work out how to keep the littlies in the vat, without them venturing into the fish tank via the highway, you are right, even though i will have mesh over the drain hole it will not be able to contain the babies. More thinking music please.....

Maybe the ones that venture through can just be supplementary fish food

going back to the foam degrading etc......

I am intending to utilise space and have a raft culture on my pond as well as grow beds, and was researching it and found this site http://rps.uvi.edu/AES/Aquaculture/lettuce.html

"Lettuce plants are grown on polystyrene sheets that are floating in the hydroponic tanks. "Dow® Board," also known as "blue board", is used. The sheets are 2 lb. density, closed cell, extruded and unscored. The sheets are 4' x 8' x 1.5". Seventy-two (72) sheets are needed to fill the hydroponic tank growing area. The sheets are painted on one side with white, non-toxic, roof paint. Paint keeps the sheets from deteriorating from UV light. White paint is coolest and best for plants"

"A lead-free latex paint may be used but other toxic compounds from the paint may leach into the system water and contaminate or kill the fish."

I look forward to when i can offer advice from experience...

Sorry daniel, we do tend to get off track sometimes

I always thought blue board was just cement sheeting that was water proofed. Obviously wrong.

I have not had any experience personally.

This is an MSDS i found for styro foam, it looks quite good. Just unsure about the flame retardant.

http://www.aeromfg.com.au/html/styrofoam_msds.html

as for the UV exposure, for small installations you could always stick white plastic to the surface. A plastic is available from hydroponics stores that is white one side and black the other. It blocks light out completely but the white side reflects some light back up to the plants and also keeps it cooler.

Here is a MSDS for the flame retardant. I guess it just depends how much is used and how much can be released or leach. as its a closed cell foam that does not absorb water it would only be the surface area in contact with the water that could contaminate if that was possible.

http://physchem.ox.ac.uk/MSDS/DE/decabr ... ether.html