Backyard Aquaponics
A place to discuss aquaponics

Like the idea its just that they weigh approx 2kilos and are usually made of PET. If it was cement, which takes a while to go off and I would not have thought could get a good grip on the PET (and is prone to cracking on a roof) how would you hold them up?

A good question. Definitely something to figure out.

If you could get a rubber sleeve then just replace the bottle if it cracks. Wonder if you'd get a similar effect with a square cube of glass filled with water and bleech. I've installed 600mm x 600mm skylights and the light from these are good.

I would think it was a tight fit and some glue personally. in order to give the glue/cement time to set, you would probably set the bottles whilst empty, then fill from the top before protecting the bottle cap with the film canister. Clearly the bottle caps are much more susceptible to UV than the PET, else he;d not bother covering them.

Plus thats where the light get through.

Think the're ususlly made of polypropylene KP

without looking again....doesnt the bottle bulge out at the top....so it would be a snug fit and probally just some sikaflex or sillycone

Yup, this is what I was saying.

Couldn't see from the pics but found a 1.25 litre which has a slight bulge (looks like just above where the label sticks on).
Thank you

Would a uni seal work well?

The corrugated sheet they are using seems to have a much larger radius of curve than what we have so you would need to make some sort of flat surface in order to install one on most sheds in Australia.

However, woudln't you need to do this anyway?

Uniseals should work if they make the right size.