This question was posted by user 202. As can be seen from the edit history that the question was incomplete at first(though I didn't knew that till today) (the previous question was scattered all over the post (and till now it almost is).
The initial question was:
Using Bernoulli's equation, it can be shown that the water velocity depends on the height of a tank relative to the end of a hose. In reality I find a smaller hose produces a greater velocity on exit than a larger hose. What have I overlooked to cause this disagreement?
$v=\sqrt{\frac{2(\rho g h-Losses)}{\rho}}$
The OP gave a bounty of 150 reps and I therefore invested some time to answer the question as it was in original form (but I also gathered the spread out information from his/her comments,etc.) and then I discovered today that OP found that his/her original question was lacking information (which was much crucial in answering it).
But as can be seen from its current form the previously given answers have now became irrelevant (though I have modified my answer).
So what should we do now?
The dilemma is due to the fact that without this newly added information the question becomes trivial but the answers become relevant and with this information the answers become irrelevant but the scope of the question increases.
Also the OP provides most of the information in his/her answer.