Backyard Aquaponics
A place to discuss aquaponics

as the beneficial bacteria are sensative to light, would it not be worth while using a darker plastic, or somehow darkening the plastic (line it, paint it....)

AM, they are only sensitive to light when they are free floating in the water coloumn. After a few days they will colonise a surface upto a few mm deep and the light shouldn't bother them.

Don't want to be a downer, but is it safe to use those types of crates in these systems. I would not think that they are food grade or UV stabilised. I have just posted something to the old thread about this sort of thing, trying to get my mind around what sort of containers one could buy from B for this sort of thing.

I only buy those containers which have the markings undernieth which specify that it is food grade - no marking means no sale for me!

VB, you spoil sport!

It was actually the fisrt thing i thought when i saw neals system, but i 'repressed" the though becasue of how portable the system is and the fact that the B is open today (sunday)

AM what markings denote it as food safe?

only problem i see with a system like that is wild temperature swings

You could clad it in styrene...

I posted info in Questionable construction materials and/or leaching
I only use the 1 through to 5 ... most in 'B' are 5, same for overflow and crazy clarks

The plastic crates I have been using have a knife and fork symbol on them so I assume that means food safe. (or suitable for storing cutlery!?)
I'm not deterred, but I won't be using the same growing media again, need to buy some more. I'll wait a while before going to get more fish in case the same guy serves me and wonders what I'm up to!

Manufacturers are quick to let you know if their product is food safe with the appropriate symbol's... I have never seen the knife and fork symbol used to indicate this before...

Just tell him they tasted good and you want more... that will get his head in a twist

spew neal, that means you'll need to go though the whole start up cycle again!

interesting about the knife and fork symbol. where did you buy them, and what were they sold as?

I made a bit of a boo-boo on that symbol, its' a fork and wineglass, the EU symbol denoting a plastic is suitable for food contact use.

I just realised the ones I used this time were from a different range in a UK DIY chain called B&Q and didn't carry the logo. But, the boxes for the next system do have the logo and are coming from http://www.reallyusefulproducts.co.uk/uk/index.htm - it's Europe only. These ones also say on the box they can go from -15 degrees C to +80 degrees C.

I think the design of the 'doomed system' was a bit flawed too: the hole in the top cotainer was to small for access for anything other than feeding. Even filled with clay balls the grow bed was quite tough to lift off without freaking out the (already stressed) fish. One of my main problems is making the thing toddler-proof, that's why I'd put the grow bed on top.

Checked almost all our plastics and no fork and wineglass...definately a european thing then...
The toddler problem, know it well... the only 2 things that have worked are to place the precius items in another area/room under lock and key or to just give up on the idea (which is seldom a true option...)

Pretty nice installation. You are using the same three-legged pump as mines. I would start over using food compliant, as Steve says there is an 'eatable' silicon. Much more expensive, unfortunately.

Just reviving this thread because I had a question on the best type of waterproof sealant to use in conjunction with poly tubs and rubber tubing, as these are the components I will use to build my next system.

I purchased Sikaflex Marine which was one of the more expensive ones and was certifed for food contact (which was more than the other sealants boasted) but found that it didn't bond with my plastic tubs very well.

What brand/type of sealant have you guys found to be the best?

Johnnie, this is the one I have used. Not sure about its food safe specs, but it says neutral cure, which I presumed to mean it's probably okay. Sticks really well to rubber, I have used it on a Aussie connector rubber flange as part of joining my two tanks together.