I have a 20 watt light on my 29 gallon tank right now and I would like to upgrade so it is a bit brighter and can have moderate light plants instead of just low light which it currently supports. I just don't want to have to put too much money into it at the moment. I don't have a glass top, just the plastic hood with the light that fits onto it. Are there any other options in light bulbs that will work with my current fixture which I believe is one T8 bulb? Otherwise are there any good value T5 strips I could use or am I looking at an expensive new setup?