I was just reading on a Singapore goldfish site that long term life indoors eventually weakens GF and possibly shortens their lives, that they need to be outdoors...

It does make sense that they need UV light for their coloration etc, but would ambient indoor lighting and artificial aquarium lighting be sufficient for their long term health? Light travelling through glass does have some aspects of the UV spectrum filtered out...maybe that is part of the issue?

I have also noticed that the better foods contain a Vitamin D supplement (I'm guessing GF synthesise Vit D from the sun like we do?!). Maybe the Singapore site was referring to Vit D deficiency??

I have wondered about this before today and thought about putting them out in the backyard in a large plastic tub for some sunbaking every week. Then I thought through the logistics of doing that - matching the water temp/ph/preventing cat attacks/catching them etc etc - all too hard and possibly more stress on them than potential benefit. I've also thought about installing a skylight in my living area to increase the ambient light for them (and me!)

What do others think of this whole concept? Does living indoors harm goldfish?

UV, or not UV - that is the question

Cheers, Helen

It is unmistakeable the differences in a goldfish kept outdoors in a pond and a fish that is kept in a tank. But that does not mean indoors HAS to be less. In general, the various colors of the spectrum in the full sunlight do help increase colors. The large volume of the ponds tend to give ample volume to a fish - far far far more than the 10-20 gallons per fish most get in an aquarium. Ponds are also, commonly, a constant source of food - algae, bugs, etcl are nearly always available - a fish can nosh on food pratically all day. If the fish is kept in green water, it does eat all the time - so the size differences can also be dramatic.

I think that tank culture CAN be made to imitate a pond environment - or very nearly so. Proper lighting - the right intensities and spectrum, good food, large water volume, pristine water conditions can all go a long way to making the fish as good, healthy and hearty as a pond fish.