well yes, that was ok to do it that way. I didn't mean I plunge them into instant darkness......lol.
A few real plants would help in your tank and they are quite cheap to buy, and can be quite pretty.
Is this the first time you have had fish? One golden rule, which many people make the mistake of too, is try not to overfeed your fish. I only feed mine every other day. too much uneaten food in the tank rots away and causes pollution.
another tip is to buy a fish magazine now and again, they have lots of tips in them. Practicle Fishkeeping is the best.
happy fishkeeping.............. :-)