Backyard Aquaponics
A place to discuss aquaponics

I've been temporarily using part of a cattle panel from tractor supply as the safety cover over my pond/tank. Now that things are starting to shape up in the system, I'm looking to set up the more perm solution. Then I realized I should check on the materials of that cattle panel. It is zinc coated!!! Ack, good thing I was working on some water changes before getting fish.

Anyway, to the point of my question, how bad is the zinc coating? In other words, If I were to use some of the panels to allow vining plants to climb over the grow beds, am I asking for trouble? I had been planning to make an arch over the whole system using the cattle panels which would allow large vines to climb up and provide shade during the hotter months and it would provide support for cold protection during the few really cold nights.

I am now wondering if this is still an option or if I need to look for others. The cattle panel arch is a really cheap way to make a shade or cold frame structure and the wire openings are a great size for tomato cages or cucumber tunnels.

I will probably make some other sort of cover for the pond/tank so water can't drip down into it directly but the arch would be over the grow beds too and there would be no good way to stop all water dripping from it into the system. How extreme is the danger to the fish?

I doubt such a small amount as moisture dripping from the mesh would cause many problems. The plants would likely remove it from the water and make use of it. Polytunnel frames are hot dipped galvanized (zinc)

I've been doing a little reading into research on the subject of zinc toxicity and am coming to a similar conclusion.

Using a galvanized container to stew an acidic food can cause toxic effects on a human that eats the food. Using a galvanized vessel to transport your fish fry can cause major grief as would using an uncoated or lined galvanized tank.

Zinc toxicity is also linked with water hardness or lack there of as well as pH. As in the allowable limits of zinc in the water goes up as the hardness increases. Zinc can become more dangerous in more acidic conditions.

As I have a huge amount of shell in my system, my water is plenty hard and the pH will likely stay above 7 with no problem.