Subject: How can the amount of lumens be different for bulbs with the same wattage?

I am thinking of performing anexperiment, testing the effects of different kinds of light on brown 
planarians. I am using incandescent, CFL, and LED bulbs. I want to have all of the bulbs have the same 
lumen output, and not necessarily the same wattage. I did some research online, and I found that a 25 
watt  incandescent bulb has 250 lumens, and that, in order to get 250 lumens in the other two bulbs, I 
would need a 4 watt CFL bulb and a 3 watt LED bulb. I found a three watt LED bulb, and then found out 
that it was only 60 lumens. Hw can that be possible? How can two of the same wattage of bulb have 
two different lumen amounts? I would be very thankful if you could answer this question for me. Thank 
you so much for taking the time out to read this. Thanks again. 

Sincerely

Casey Acklin

Re: How can the amount of lumens be different for bulbs with the same wattage?