Is ventilation necessary?

[LiamCH]

My second hand tank came without a lid, and after a bit of searching I've managed to find a clear plastic condesation tray that fits it almost perfectly. The thing is though, apart from a miniscule gap for the cables and four small air holes I made, it doesn't really allow much air into the tank. Would that be a problem? I don't want to go and bodge loads of holes in it if I don't have to, as that will let more condensation into my room, but obviously I want there to be enough oxygen in the tank.

What would you reckon I should do? I haven't got an air pump yet by the way (which shouldn't be a problem as I don't yet have fish!) but I'll be getting one soon.

 

[mattrox]

ANy lid which is not air tight will be fine...... a miniscule gap allows air to access the water's surface.

 

[BigJim]

It really depends on how tightly the top fits and what kind of filtration you're using. A HOB filter works well with a tightly sealed top because the HOB agitates the water a lot. A canister with a tightly sealed top isn't so great because the canister is a sealed system and doesn't allow much gas exchange.