hey babycakes first id like to comment on AMAZINGLY beautiful tank!!! BTW whats the set up?? and I cant seem to find the 7.5g long on the glasscages.com
on that site under acylic, its labeled 1/2 - 15, dimensions are 12 1/2 x 24 x 6 1/2 tall. im thinking about the 1/2- 10. they are really good prices too.
you dont really need one, only if your not going to be at home everyday. i dont have one but im here everynight to check the level. it wouldnt be that bad since its only 7.5 gallons, less with LS and LR.