Hey guys Im here to ask, I have 4 goldfish that are being held in a bowl! I know its cruel but im not allowed to buy anything bigger until my aunties gets be a tank, still the tank is only about 1.5 gallons and I know its not good for the fish.

In order to keep them healthy what is a cheap filter I can have?

So, you wish to keep 4 fish in something the size of a lemonade bottle. Each of these fish can grow to be a foot in length.

You do the maths

You obviously need at least 40 gallons if you have double-tail fish (fancy) or 80 gallons single-tail (comets, shubunkin, commons). I suggest rehoming them or just giving up those fish in general. Second of all, cycling a tank under 5 gallons is as useless, so the point of a filter is rather diminished. Finally, when keeping fish, their owners shouldn't wonder what is the "cheapest", they should wonder what is the best for their pets. Not having the money or respect for pets to get them what they need to thrive is pointless.