Backyard Aquaponics
A place to discuss aquaponics

[code][/code]In three months time I will start to build our aquaponics system. The shed is on order (12m x 5m x 3m). I will work with 3 IBC tanks for fish and will have a 2000 liter sump tank which will be under ground. (CLFT/PIST system). The three fish tanks will overflow in one another and the last tank will overflow in the growbeds.

Now; I want to install grow beds with a total capacity of 4.5 m3.

Here are the sizes of my ideal growbeds:

3x 2500x750
2x 1750x750
2x 2000x750
2x 1500x750

All growbeds are 300 deep. Total volume = 4 m3, total area is 13.5 m2

Does anybody know where I can buy good quality fibreglass growbeds at a reasonable price?

I received a quote from a reputable fibreglass tank manufacturer in Sydney but their quote came to $5800 delivered to Melbourne!
The growbeds do not need necessarily be made out of fibreglass. I would go for polyethylene as well but most of these growbeds in PE seem to be very flimsy. If only a company like Nally bins would make some decent growbeds.
Any ideas guys?
All your tips will be appreciated.
Thanks!

Luc

Have you considered corrugated iron aquaplate tanks? They are a lot more readily available, and are generally cheaper.

Getting custom spec fibreglass tanks is always going to be expensive as the manufacturer would generally first need to build a custom wood or foam mold to form the shape you require. Then lay up the fibreglass upon this.

Another consideration with "marine grade" fibreglass, despite what one particular character in QLD will tell you, is that the gelcoat (the final smooth layer) will not be potable water safe, and will slowly leach styrene into the water. This is a concern as recent research now suggests that Styrene is a carcinogen to humans. Big fibreglass resin suppliers (eg Nuplex industries) will not guarantee their resins/gelcoats to be safe for holding potable water, even if you go to the trouble of post-curing the tanks with heat to minimise styrene release, and will generally shy away from selling you resin for this purpose I've found, for obvious legal reasons. As a sidenote, it's common to see on the boating and yachting forums complaints that water tastes like plastic (styrene) from those who have made the mistake of making a fibreglass tank to hold their drinking water onboard.

To make fibreglass tanks safe for potable water you will need to use a food grade gelcoat (meeting AS/NZ 4020 standard - Products for use in contact with drinking water), and follow the post-curing procedures. They are available, I have bought and used them, but expect to pay more for them. OR (cheaper option), seal the fibreglass tank with a potable water safe bituman paint (see this thread: viewtopic.php?f=1&t=20343)

Thanks Jono81.
That is a useful tip. I haven't thought about that. Would the galvanized aquaplate tanks be ok? I'm still very suspicious about mixing metals with water (Such as zinc).
The other concern is the rounded corners. It's more space efficient if one could use square corners.
I have seen the oblong garden beds but they come without a bottom part. Can anybody recommend a manufacturer of these corrugated iron aquaplate tanks which can be used in AP? I don't really want to use pond liner, so, these tanks need to have a bottom part and fully sealed.
Many thanks in advance.
Luc

The 'Aquaplate' corrugated iron tanks have a potable water safe polymer lining on the inside of them, so no metal/zinc is in contact with the water. They are fish safe and drinking water safe.

Pretty much all new rainwater tanks are made of Aquaplate thesedays... it's good stuff

You can get them in almost in rectangular shape, with just small rounded corners.

Thanks jono81.
That is most helpful. I just had a look at some of the retailers and you're right. It is safe, looks good, there is an option for a bottom plate and they are way cheaper then fibreglass.
This forum is great!
Now I just need to find a manufacturer who can make them to size and without the drain holes in the bottom plate. Any recommendations anyone?
Any retailers/manufacturers willing to take on this job?
Thanks.

I tried to send you a PM LRAT did you get it?