Newbie fish owner? fish questions?

[StoicCrying]

How often should I do partial changes and full tank changes to a 5 gallon tank? (it has a filter + only holds 3 fish, one betta and 2 goldfish- we aren't going to get anymore).

When do I change the gravel?

Is there anything signs that I should look for in a sick fish? If so, what should I do? (I have a non filtered 1 gallon fish tank that's empty in case)
They're all happy and I've even kept the betta in one of those starter kits ( barely a gallon) before we got the 5 gallon and so far for the past 3 months nothing has happened. The betta was an on the spot decision, and I didn't even know we got two goldfish until my father showed me 3 months later w/ the new tank. I make sure the water is at an even temperature, not too warm, not too cold- checking it every 5 hours (on the request of my parents who had fish before, and kept multiple of tropical & coldwater fish- including bettas & goldfish housed together). So please, all I need is the answers to the questions I posted. Not everyone has $100 dollars or more to buy a new tank for fish ,that combined, cost less than 20 dollars.

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Is there any common problems that could happen to goldfish or bettas?

 

[Fish Lover]

Alex is right. And for good reason.

DID YOU NOT RESEARCH PROPER FISH CARE AT ALL?!?!

ONE BETTA IN A FIVE GALLON IS THE MAX. IN THAT TANK.

"WE AREN'T GOING TO GET ANYMORE FISH" THANK GOODNESS!

One goldfish needs a 20 gallon tank with double filtration. Two need a thirty gallon tank. RESEARCH YOUR FISH BEFORE YOU GET THEM.

Bettas and goldfish have different needs- they have a different diet and temperaturre requirements, and care, which you obviously ggave no though to.

Good job on killin gthose fish.

 

[Alex]

WARNING: fish people on YA will eat your face off now since youve said youre keeping 2 gold fish in a 5 gal.

 

[syph]

partial water changes should be done approx every 2 weeks with 25% of your water (so for 5 gallons, change out 1 - 2 gallons every 2 weeks)

never change the gravel...

if your fish are sick you will know. but never put fish in a nonfiltered tank!!