I have two air pumps in my tank one with the filter and one separate, would it be ok to turn the separate one of at night and leave it on trough the day, I only put it in today
I don't use air pumps at all unless it's for a sponge filter. As long as your fish aren't gasping at the surface for oxygen, you don't need the second one unless you like it there.
Yes save your leccy and turn it off at night, don't really need one if the filter gives decent surface agitation, so may as well turn it off when you can't see it.
My air pump is on the same timer as my light. I have live plants to they give Oxygen in the water for my fish, the air pump is just a 'feature' in my tank... when im in bed, its not needed!