Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: Great For Awhile

The good: the filter is quite easy to install(although I needed pliers,which the instructions said were not needed). The water quality is really great.The not-so-good: You must change the cartridge every 2 months. The company claims you simply turn theold cartridge counterclockwise and install the new replacement cartridge. I tried it,and found that the originalcartridge would not turn at all. Now the unit leaks slightly,and I must buy the entire unit if I am to continuefiltering water with this product.My bottom line: a new unit every 2 months.