23 watt are the highest wattage CFL most home improvement stores or WalMart sell. You can find bigger, but they cost a lot more. Most people using CFL just buy a whole bunch of them and mount all the sockets on a board painted white to reflect light down. You need two of those 23 watt bulbs per square foot of growing space, so for your 4 square foot tent you need 8 of them.
With CFLs you can put them within 6" of the plants if you have enough cooling. I use 14 watt LED bulbs with the diffuser cut off on my new plants.
They put off a piercing white light and much less heat than CFLs @Peep67. I got mine for about $3 a bulb in 8 packs on Amazon.
Certainly more efficient and they have the advantage of only putting the light out on one side. Lots more expensive though. If you want to spend for LEDs, I would recommend current generation white COBs. Or just buy a LEC fixture.
Thank you.
I appreciate your help. I purchased my grow light at Lowe’s. it’s a long stick type light. I’m not sure what the distance should be. Should I hang it 6" above the plants?
If it’s not too hot at 6" from your hand then your good to go @Peep67
Hi I agree with @Niala on the space issue. I have similar situation with a grow box of 15w x 11d x 31H. I start the grow using a 150 watt UFO full spectrum LED light and perform topping and LST after 3 or 4 nodes have grown out to help keep the plant low and spread-out. After switching to flowering and experiencing the stretching I have to switch over to CFL lights and perform more LST as the led hanging setup takes up too much space at the top. Adding 2’ T5 lights is something I will check into 
Running out of room at the end is a disaster. I don’t know why so many people try with tents or boxes that are so short. Most strains will top six feet.