Galvanised Bath

[MHunt]

Hi, my parents have made a small pond in their back garden out of an old galvanised tin bath. They have added a couple of goldfish which have been ok for a couple of months now, but one has died recently, and the other is beginning to look a bit ill. I couldn't guess on the size of the pond, it is unlined, with gravel as a substrate. There are several potted aquatic plants with pondweed as a floating plant in the water. There is no technology used such as a pump or filter, they do periodic water changes but I don't know how frequent or how much. I don't have any test results.

Could it be the lack of filtration, or perhaps is something from the bath poisoning the water slowly? The fish are quite small, but i haven't looked closely to see if they are causing much waste.

Your advice is appreciated.

 

[GoldLenny]

A purely natural pond with no filtration or aeration would need to have atleast 100G per goldfish and lots of plants to handle the amount of ammonia put out by goldfish. Having gravel as a substrate probably makes things worse as it holds too much detritus which makes it harder to remove when vacuuming the substrate of the pond.... that's presuming they vacuum the substrate when they do PWC's. Without know more info on the size of the pond, it's difficult to give specific advice. Can you post a picture of the pond and take measurements of the length, width and depth?