Sand filter should be a pool of 20000 liters. The size of the plant is the can not afford. I opened the carton and immediately requested the return note. As the supplier has not reported so far with me - according to Amazon should let the company 2 days, now are already have 5 days have passed. There was also no bill here (which would in case of warranty?). The manual is in English. These are all reasons to issue a negative feedback. I'll report how the rescission ran.