Instruct: Classify Amazon reviews into positive or negative sentiment
Query: BEWARE - These new pumps are made in China - Noisy under back pressure

Let me start by saying I love maxijet pumps. However these newer ones are now made in China. This may or may not make a difference to some people but here is the issue I came across. I use this pump to feed a reactor for my fishtank. Normally I use a ball valve to throttle down the flow to keep my carbon from grinding itself down to powder. With the old style pump this was no problem, I could dial it back and it would work as quietly as it did unrestricted. With the new style pump made in China the machining process must be a little more laxed or something as ANY back pressure at all makes these pumps rattle horribly!Be aware of this issue if you plan on using this pump to feed a reactor, or skimmer or anything else that might cause some back pressure. The noise will drive you crazy!