WOW! When you get to be my age you tend to question what people try to sell you or give you advice.Every Pond Co. uses what they can buy at a good price. By asking strangers on this forum who have or had the items i am asking about, it's like getting a Review. So if you can't give any help-full advise then you shouldn't reply.
Yup - you took it the wrong way.
First of all, I have no idea what age has to do with anything - I think many people research products before buying them no matter how young or old they are. And I definitely don't agree with you that all pond companies use whatever they can get the best price on - a reputable company will use equipment that they know is reliable and long lasting if they want a satisfied customer. If I felt that someone was only trying to sell me something because it benefitted them, I would question their business ethics on all fronts. But that's just my opinion.
Sorry if you felt my comment was unhelpful. I will refrain.