Pouring Water into my Secondary?

Just transfered my first brew from the primary (bucket) to the secondary (6.5 gallon carboy, at least I think it is 6.5 gallons, i realize now I should have measured) and I am not sure how much beer is in there.

Anyway, it appears that there is not 5 gallons of brew in the carboy. Looks like 4 gallons to my eye, but what do I really know. Should I add water or I just leave it alone?

I think I should just leave it alone but looking for some reassurance. Next time I will make sure there is 5 gallons when I put it in the primary before I pitch the yeast.

Thanks for the help.

Leave it alone.

What style, what is your specific gravity?

I almost ALWAYS come up short.

Leave it be, the only difference in the end is stronger beer!

Thanks. That is what I figured.