With respect to the administrator, intention was not to hurt feelings. Adults need to be able to speak honestly and frankly or why bother communicating. The pump for a given pond / waterfall effect is one of the most discussed issues in pond "literature". One could crosscheck 4-5 different sources quickly--take notes, it's a lot of information.
At that point you're looking for consensus, e.g. I'm planning on buying pump A--anyone had problems with it, did it perform as advertised? (I measured the output of one pump I tried and it didn't) If more than one person writes in with issues, then reconsider.
Why does someone write in to a forum and ask for help? Think about it. There are other reasons to write in, e.g. sharing information, discussing projects, outcomes, etc. But to write and hope to engage people to get their assistance is asking for their time and knowledge.
Wasting people's time is not a small matter. Certainly I have done it. Still do it, but I try really hard not to. I am always learning, changed careers X 3 and roles more times than that. I choose to be the novice because I love to learn--but it's often not fun because I get to be the ignorant, neophyte again.
So, I've become very aware of the importance 1) to think before asking, 2) do my research and educate myself to see if I can answer the question myself, 3) cut bait, make a decision, and assume risks at some point and 4) steel myself to the criticism I earn when I fail on 1, 2, or 3.
I go in pond shops and am amazed at the level of questions people ask. You can read the product box and get them answered. Also, at times the salesperson will "hold forth" and give advice that, even in my limited knowledge, is questionable. Might even be wrong--lots of people hold forth as "experts" who are just good at BS, but don't know squat.
To me the pond subject is highly complicated with many, many variables and equally many pitfalls one of which is wasting money on choices that don't turn out. It's the price of getting into a hobby--no guarantees.
So, figure out what you want, what you can spend and do your research. Then, if you can't find answers ask for help. Otherwise, it's really interesting to see your results, hear about your successes and failures and to chat about the topic in general. It's why I'm here.