12v t3 vs t4 gy6.35 pool light bulb. Whats the difference?


New member
Jan 12, 2017
Palm Bay, Florida
I need to the replace the two in my in ground pool light. I believe the socket is the same. So what is the difference? I have the t4 100w available in the area, but will have to order the t3 online. Any reason not to use t4 when they are the same watts and voltage and fit the socket?