Hi Customer (name blocked for privacy). From what you have described it appears that the water in your goldfish's two gallon aquarium was doing him harm.
If you haven't changed the water in a long time
,ammonia, which is very dangerous to fish, could build-up to toxic (deadly) levels. Also when you put your goldfish in the fishbowl I hope you used a dechlorinator. Tetra EasyBalance is not a dechlorinator. (I have listed below a website
which will give you complete information as to what Tetra EasyBalance does). If you didn't
add dechlorinator to the goldfish's water you
must take him out of there immediately or add dechlorinator or he will die from the chlorine in the tap water.
In direct answer to your questions- the yucky smell was either an ammonia or bad bacteria build-up. The slimy mess all over the tubing and filter
are normal in aquariums. The goldfish became lethargic because of the poor water quality and
probably had trouble breathing which caused his
lethargy.
You did the right thing changing his water. So for the future, change all the water in his two
gallon aquarium every 3-4 days using dechlorinated
water. If you do this the filter will not really play an important role in his aquarium but is still good to have. Make sure you replace/clean the filter media (cartridge, sponge) at least
once a month. TetraBalance is meant to be used
on established aquariums and supposedly takes
away the need to do water changes but I do not
recommend avoiding water changes. Think of it this way--a water change to a fish is like what
a breath of fresh air is to us humans.
Another very important thing is to not overfeed
your goldfish as this will pollute his water.
Feed him only a little bit (what he can finish within 3 minutes) twice a day. I know he may look and act hungry but it's to his and the water's benefit not to overfeed. Please let me know if you need anymore help and I'll be glad to share
my information with you. Good luck.
www.tetra-fish.com/catalog/product.aspx?id=74