How much gravel should be in an aquarium?

[BettaBabe]

I have a very small aquarium 2 gallons (us). I am planning or giving it a really good clean this coming weekend. My fish has fin rot and isn't getting better with treatment. I have been doing water chngse weekly for years but I never thought to clean out the place where the carbon filter goes and it is brown and gunky. I also, noticed that my gravel is filthy! I have about 2" of white gravel that is now brown. I am vaccuming this brown stuff weely as well.

So, how much gravel should I put back in the tank when I've got it all clean up?

BB

 

[CFC]

For a tank with no plants and no fish that like to dig a substrate of 1/4 inch will be fine.

 

[Nina7777]

in my 2 gallon tank I have an inch and a half of gravel. Does it have an undergravel filter if so then just use enough to cover the plate.

 

[BettaBabe]

in my 2 gallon tank I have an inch and a half of gravel. Does it have an undergravel filter if so then just use enough to cover the plate.

No, it's a bio-wheel. Since Beaux got sick with rot I have learned that the filthy tank was the cause. Even though I keep the water cycled the brown gunky buikd up must be the reason for the rot.

So, anyways, I will clean it really good this week and only put back 1/4 of the gravel.

BB