I have a 125 gallon planted tank (18x72x24) that has been lit with two 182 watt T8 light systems. These systems are over 10 years old and they are falling apart. The bulbs fail regularly and I am continually replacing them. The hardware itself is also deteriorating. I am looking at a Tek Light T5 Fluorescent Aquarium Light 4ft 6 bulb 324W system. Is this sufficient or do I need to order an 8 bulb system. These are quite expensive so I want to make certain I am ordering what I need. I would appreciate any help.