I wouldn't use the clear vinyl for pressurized water: and, if you're "sucking" out of a tank, I wouldn't use it either. As others have said, you really shouldn't use the clear vinyl with hot water.

The diffenence that defender quotes for 5/8" is $1.49 vs. 1.79/FT and 3/4" $1.79 vs. $1.99/FT (Clear vs. Reinforced).

If bought it in "bulk", you might save some bucks -- certainly worth a call to compare pricing with various sources. IF you use 100 LF -- you're talking $20-30 or so in price?