My tank has a good filter but also an airstone in it mainly for looks and the fish like swimming through the bubble wall but should i turn the air stone off at night, will it disturb the fish sleeping
I don't think it matters. My airstone stays on all night and so far my fish don't seem to have bags under their eyes Ha, seriously though, it will increase oxygen levels for your fish so probably best to leave it on.
It's a stone that helps oxygenate. You attach an airline to it and then it runs off a little separate motor. If it's positioned at the base of the tank can create a nice bubble wall effect
On a larger or overstocked tank an air stone is great for extra oxygen. Yours should be fine but you can use an airstone for visual effect if you choose to.
You don't NEED an airstone unless your filter does not cause any surface aggitation - but it does increase oxygen levels (which is why it doesn't do plants any good - during the day at least )