[Elynnei]

So I've been told to use a filter designed for double the tank size. So one for designed for 55-60 gallons in a 30 gallon tank. I have a gourami in there, would that make her too upset from too much surface water movement?

 

[ichthyogeek]

Well it always depends on what type of filter you're using.

For example, a HOB that's rated for double the size of a 30g will cause a lot of movement, but a sponge filter rated for a 60g won't. Canister filters are variable as well.

What type of gourami, and are you upgrading or sticking with your original tank? And who gave this advice?