Backyard Aquaponics
A place to discuss aquaponics

I live in a tropical country and trying to grow cool vegetables like lettuce. I'm using DWC and Tilapia.

I plan to cool down my water by using a cold water source and just run a coil of copper through the nutrients. Will copper be safe for my fish and plants?

Copper is toxic to fish,problems can start with levels as low as 0.01 ppm.

Would it help if I lightly spray the copper tubes with latex paint or something? Anybody with an alternative solution would be highly appreciated.

No it will not help.

Use an intermediator.

Create a plastic closed loop for your fish water (if you have a lot of money then stainless steel is better), run that from an insulated barrel to the fishtank and back, then run another closed loop with your copper, that will run from your insulated barrel to your cooling source and back.

Plastic is alot cheaper as well.. Copper will also react readily with the system water once you system starts to become acidic.. it will thrm kill out your bacteria and later your fishes

Fwiw ....

I am in the process of converting an old portable aircond into a chiller..

It cost me about thirty bucks for a six mtr length of 8mm stainless tube that I bent into a serpentine that can be immersed in the water...

The AirCond was free - a junk pile throw out
..
.

Hi, I'm setting up a system in the Philippines at the moment. My primary source of piping is HDPE. Cheaper and much easier to set up than copper.

Not sure why you would even consider copper as it's not commonly used at all in the Philippines in plumbing anywhere that I know of.

Regards,
Woodrow.

But it is used to some degree in Refrigerators,Freezers,Aircon units Chillers etc,so if you had no experience of fish keeping or AP and wanted to make a cooling coil it would be a easy choice to make as it looks right,he did the clever bit of asking here for advice before he went ahead and used it.

Which works best? PVC or HDPE? Thank you!

Hi Mariebelle,they both work as well as each other in the job they are chosen to do,both have there benefits i believe HDPE is stronger and harder but needs to be thicker than PVC to withstand the same pressure but thats not something we have to worry about in AP,i personally have used PVC as its cheap,readily available, its strong light and works as well above ground as below,i think you will find most members have used PVC pipe work and fittings.

it depends on application Marie.
In this situation i would use a thin walled poly hose, like irrigation hose.
plastic isnt a good thermal conductor, so the thinner the better.

Why wouldn't it help ?
As long as there is no copper coming in contact with the water.
It will deminsh the cooling a bit but I can't see there being any reason it would not work
The biggest problem I see for this idea is pumping the cold water through the coper pipe
Very small diameter, lots of pressure needed.

because the threashold is very, very low.
i used galv. tanks at the start, i tried coating with polyester fibreglass resin, that peeled/ cracked off after water got in behind it.
i then removed that and coated in crommelins water proofer for metal (http://www.bunnings.com.au/crommelin-1l ... r_p0961573) and even though i did more coats than they say is needed, the zinc level shot back up to the same levels as when there was no coating in 1 week.

I have now coated the last one i kept in a thick coat of fibreglass "flowcoat". This will now be used for yabbies but may still be a failure. it has basically become a thick plsatic coat inside.

The lengths needed to go to to ensure that there is no leakage is over the top, you are simply better avoiding the materials in the first place.

Also with such a pipe and low pressure pump you simply run a manifold and many small tubes rather than one long one.

Hey, thanks for the response. I've plans on using PVC as well. But I'm open to any better suggestions. And Thanks Yavimaya for explaining that. I'll keep an open mind. ;D

I could be wrong here but the way I read Dasboot's post it seems like he's referring to the water plumbing in AP for the PVC and HDPE use.

Anyway, I was asking for help with the tubing to use for cooling the water. Thanks for the input about the copper toxicity. I'm now trying to find stainless steel tubing coils... 4 days now, so far no such luck yet.

Regards,

-Ronald-