Having had 3 years experience with goldfish I will pass on my advice. I had a 30 litre tank with 2 goldfish, an external filter, a couple of fake plants and a couple of ornate pieces and I got to know someone who kept goldfish for 40 years and told me that after 3 years of seemingly happy swimming around that mine were dying after being constricted in small space. I needed at least 100 litres, with no obstacles (apparently they can injure themselves as they are clumsy swimmers) and should be kept in groups of 5 or more to give them social structure. I felt bad for them so gave them to him as he had 4 ponds and 4 250 litre tanks all varied goldfish breeds, and mine have now grown to about 5x their size when I had them and they are approx 5yrs old now. Although one shows signs of age and has discolouration and less active, the other is thriving and they are in a tank of about 10 fish.
Now I know for fact that goldfish grow and grow and need a lot of swimming space as constricted space causes them many health problems but I don't believe the social structure is as complex as he was telling me. I think all fish are clumsy swimmers, and can see his point but surely fish shops and stockists wouldn't supply or have ornaments in goldfish tanks if that were the case? I know that fish shops are not to be believed on many things as they sell 10 or 15 litre tanks and will happily sell larger fish for these setups but actually demonstrating bad practice?
Anyway I waffled a bit, my advice is to get a bigger tank, but I wouldn't add anymore fish as this can overstock and cause many problems and undue stress to the fish unless you get a much larger tank. Fake plants are a good addition although mine did attack it somewhat for the algae that formed on the leaves of it. I also suggest a good filtration to help clear it with regular water change. I know my goldfish produced a lot of waste. Good luck with your setup!
Sent from my iPad using Aquarium Advice
