just got a new 6 gallon tank iv always had gold fish but my mum keeps tropical just wanted to ask with all the heater and filter would this size tank be ok for tropical or should i stick to gold fish

I would invest in the heater and go for tropicals. Goldfish can grow quite large and would be too big for a six gallon tank. A single fancy goldfish ideally needs a 15 gallon tank to itself and common goldfish should really be in a pond. The small investment for a heater greatly opens up your options as you can move into the much larger, more interesting and colourful world of tropical fish.

Fortunately, there are quite a few tropical species that are ideal for small tanks, and many species can be hardier than goldfish. Microrasboras, Siamese fighting fish (Betta splendens), Spotted Blue Eye Rainbowfish (Pseudomugil gertrudae), Ember tetras (Hyphessobrycon amandae), Sparkling gouramis (Trichopsis pumila) and Cherry shrimp (Neocaridina heteropoda "red") are all just a relatively small handful of options that you can consider.

by my calculations, 6 gallons is roughly 27L, which im sorry to say is too small for goldfish anyway. even the smallest types of goldfish require about 40-50L per fish, with the larger goldies needing at least 90L per fish, preferably in a pond.

that tank of yours is really only of use as a tropical tank. a small heater and filter is all you would need for the tank, and you can keep a small number of small tropicals

cool thank you will go get a heater and filter then

good luck! im getting a tank given to me next week. Ive got my heart set on a fancy goldfish but if the tank is under 50L (i wont know til i get it) im going to get tropical fish as the tank does come with a heater and filter.
Im quite excited! let us know what fish u get to give me some ideas