chishnfips
WHAT! You went over my Helmet!
below are two links in both of them you will be able to see clearly the differences between tropical and coldwater fish.
Generally from my experience tropical fish are far more colourful and take on many different forms.
where as
Coldwater fish seem to all use similar colours (for the majority that we see in the pet stores) usually golds whites, yellows, blacks and greys and all seem to look quite similar (to me anyway)
.
I hope these links help you.
as for the the tetras, they will probably seem ok in the tank as the damge that will be caused will be long term and maybe not as noticeable, as tokis said you might see different actions in their behaviour, and feeding patterns.
As you have a heater in there then it would be the goldfish that aren't comfortable, unless you take out the heater and rehome the tetras. If you think of it in terms of, if you were a goldfish and loved the cold water would like to live in a place that was too hot? And vice versa for the tetra.
As for the filter, if you had one in the tank it would firstly save you alot of work with the water changes, and it would also help maintain a good equilibrium within the tank, it keeps the water moving, helps oxygenate it, filters out the poop and uneaten food. without having a filter you are risking the build up of amonia and nitrites, which are poisinous to your fish.
The lfs that you bought them from has not given you good advice and just wanted a sale, its not you that is at fault, but good researching before you buy is always a bonus
.
goldfish link
(click the link and go to photos on the left hand side)
tropical fish link
Generally from my experience tropical fish are far more colourful and take on many different forms.
where as
Coldwater fish seem to all use similar colours (for the majority that we see in the pet stores) usually golds whites, yellows, blacks and greys and all seem to look quite similar (to me anyway)
I hope these links help you.
as for the the tetras, they will probably seem ok in the tank as the damge that will be caused will be long term and maybe not as noticeable, as tokis said you might see different actions in their behaviour, and feeding patterns.
As you have a heater in there then it would be the goldfish that aren't comfortable, unless you take out the heater and rehome the tetras. If you think of it in terms of, if you were a goldfish and loved the cold water would like to live in a place that was too hot? And vice versa for the tetra.
As for the filter, if you had one in the tank it would firstly save you alot of work with the water changes, and it would also help maintain a good equilibrium within the tank, it keeps the water moving, helps oxygenate it, filters out the poop and uneaten food. without having a filter you are risking the build up of amonia and nitrites, which are poisinous to your fish.
The lfs that you bought them from has not given you good advice and just wanted a sale, its not you that is at fault, but good researching before you buy is always a bonus

goldfish link
(click the link and go to photos on the left hand side)
tropical fish link