I don’t think anyone here will deny that a T5 fluorescent can make a great starter light, whether you are starting from seed or creating and maintaining clones. Seedlings and clones require relatively very little light, about 400-1000 lumens per square foot and even a simple 2 foot long T5 can accomplish that in a small propagation area. T5’s can even be used for a vegetative room if done right (vegetative growth requires about a minimum of 2,000 to 3,000 lumens per square foot), and even used for a full grow if you know what you are doing and are limited to this type of light for various reasons.
As for 24 hours of light during propagation and/or the vegetative cycle, this can be very controversial and even Latewood and I don’t entirely agree on this. Latewood believes the plants need some rest, and although I agree that root development and some other biological process can be helped with a dark period, I have never had any problems running 24 hours of light in my propagation or veg, and many other growers also practice this and swear by growing with 24 hours of light during these periods. A specific strain may be more or less sensitive to possible problems being grown this way, but as for me personally, I have never run into any problems regardless of strain, so far.