Fish safe coating for container?

[bagsmom]

Hi everyone! We found out the hard (and sad) way that a galvanized metal container is not safe for fish. My son did a really nice water garden with a fountain in a galvanized trough. The plants are doing well, but the two tiny goldfish died. I googled this (after the fact, like a dummy) and found that it's not safe. If were to dismantle the set up and remove everything, is there any product that we could paint onto the metal that would seal it, and make it fish-safe? Otherwise, we'll just resign ourselves to enjoying the plants.
Thanks!

 

[MitchM]

I wonder if the goldfish died from ammonia poisoning.
Did you cycle the tank first?
I wouldn't trust the coverage of a spray on or paint on product. What about lining the tank with a rubber liner?

 

[addy1]

Yep agree ^^^, test your water, that could have been the issue. Ow a small piece of liner would work great.

 

[bagsmom]

I don't know how I would attach the liner at the edges. It's not a pond, with horizontal surfaces. Would I silicone the liner to the inside edge?
I did take a water sample to the pet store and they said it was really great, just a little "hard." When I googled, I found several articles that said the chemicals used to galvanize metal are toxic to goldfish. I COULD try again, but I feel horrible at the thought of using a "sacrificial fish." Even if it only costs fifty cents, it's still a little fishy!
Here's a picture of the water garden.

 

[MitchM]

I'm not convinced that it was cycled properly.
What did you do to set this container up?
Buy it, add water, add plants, add fish.
What was the time period for all these things?

 

[bagsmom]

We put out water and treated it with the chlorine remover -- added plants and waited 10 days. Then we got the two smallest feeder goldfish we could find. Very small -- about an inch. The fish didn't act happy from the get-go. I thought they were still and kept hiding because we were looking at them from above, like predators. The first fish died within 3 days. The second died a day after.
Took water sample after the first fish died and they said the water test looked great, but that the water was just a hair on the "hard" side. It's been two and a half weeks since then. I could try taking in another water sample.

 

[MitchM]

The thing is with metal containers is that during the manufacturing process various solvents and oils are used, so if the container wasn't washed first with soap and water, that could have contributed to the demise of the fish.
Also, without a source of ammonia, the nitrifying bacteria would not have had a chance to grow to a sufficient population so that they could have processed the waste from the fish as it produced.
Time alone doesn't allow for sufficient bacteria population growth.
Pure ammonia from the grocery store would provide an ammonia food source. That's what I use. When you use fish as the ammonia source, there is the risk that the ammonia they produce could damage their gills too severely before the bacteria population establishes itself.
With aquariums and ponds, water testing is a necessary ritual.
I suggest buying some water quality test kits, like ammonia, nitrite, nitrate and see what the numbers show you.

 

[bagsmom]

Thanks! I will do this!

 

[bettasngoldfish]

I think @sissy might know what to use to seal the tank. I'm still not completely convinced the fish died from the tank though. If they were small feeder fish they most likely were sick when you bought them, it happens a lot. They are not kept in the best conditions. I dont think two small feeders will produce enough ammonia in three days time enough to kill them. Although I do agree if you want to try fish again you will want to buy a test kit.

 

[Tula]

I'm not convinced it was the galvanized tub either. I've seen others use them and have fish successfully.

 

[haver79]

Cute water feature. Sorry about your fishies.

 

[Big Lou]

Hope it all works out for the best!

 

[Meyer Jordan]

I don't know how I would attach the liner at the edges. It's not a pond, with horizontal surfaces. Would I silicone the liner to the inside edge?
I did take a water sample to the pet store and they said it was really great, just a little "hard." When I googled, I found several articles that said the chemicals used to galvanize metal are toxic to goldfish. I COULD try again, but I feel horrible at the thought of using a "sacrificial fish." Even if it only costs fifty cents, it's still a little fishy!
Here's a picture of the water garden.

Yes, the Zinc used in galvanizing steel is highly toxic to all aquatic animal life.
Someone else may have more experience, but I have always been under the impression that galvanized surfaces were hard to coat. After reading the below linked PDF, I found that my beliefs were correct.
http://www.galvanizeit.org/images/uploads/articles/paintsteel.pdf

I would use an entirely different container manufactured using safer components, like a Rubbermaid container or a large decorative ceramic pot or bowl.

 

[MitchM]

I did not know about the zinc aspect before.
Thanks Meyer.

 

[bettasngoldfish]

@Catfishnut seems to use galvanized tanks to keep fish and doesn't have trouble. https://www.gardenpondforum.com/threads/galvanized-stock-tanks.11882/