I have a tank that is 30" in length and 18" deep.

I currently have two bulbs in their 24" long - but only 18watts. Obviously
this is not enough light, but every where I look all the 24" bulbs are only
18watt, to get a higher wattage you need to buy a bigger bulb (which then
wont fit in my hood) I also can't get any more bulbs in my hood as there
isn't room for more than two.

How can I get more wattage, or are there any high watt bulbs out there?

Stu