selling this pump for friend who don't speak English, pump was made by March 2017,he purchased it from pacific aquarium on june,2017, pump works good as I have tested it in front of him in his basement before he pay on 7/11, my friend got the money second day morning, but buyer called for return 4 days later on 7/15 said the pump is noisy, my friend rejected immediately cuz he said the pump was working good when he brings to me on 8/9,he said he didn't know what's happening to the pump during the 4 days. I try to make a compromise in between them,but my friend only sent me the recipe of the pump, and let me tell buyer that he can call vortech for a new one by using this recipe and serial number as pacific aquarium guy told him, I texted the buyer back, but this morning(8/16) he already give me a bad review!!! Show this bad review to my friend now he agreed to return the money back to me ,too late...who's fault?