Hello, new to the forum had a question, one of my tanks is a 55 gallon, 48" long and about 21ish? high. i purchased this light. http://www.amazon.com/AquaticLife-D...=1353984035&sr=1-2&keywords=aquaticlife+t5+48 i was wondering if i can add another or would that be to much? im trying to figure out how the watts per gallon works, i hear with the t5 it doesnt work the same. also if you have to much light you have to have Co2? im not trying to grow any crazy stuff and this light seems to be doing great but there was a sale and i could get one for a good price. Thank you!!