cool tube question

whats every ones opinion is a longer or shorter cool tube better? one purchase option from one company is 25" and and the other seems about 19-20" but is not specifically listed. both are basically the same price. i also have the option of an 8" as well. i will be running an 8" fan so maybe i should spring for the 8"?

all depends on your light. the bigger the bigger get that??lol if your running a 400wtt use a small tube if using a 600-1000wtt use a longer one because the bulb is longer

Unless you are in a small tent or similar space cool tubes suck. I have purchased MANY. If you are going with them get the biggest one they have. I used all 8" 600w HPS and they barely lit 1/3 of my 4x8 tables. Also the reflective material in the cooltubes reflects less light than my hoods did. Good luck!