How much light/sunlight do goldfish need? We have a bush block with a wonderful spring that I was going to use for my watersource this breeding season. My intention is to set up tanks to be fed by this spring - this would be for babies only. Problem is there is not a lot of sunlight - there is light but it filtered. Would this work? The water is warm and I have another pond (full sun) in which the babies grow like crazy.