Instruct: Classify Amazon reviews into positive or negative sentiment
Query: waste of time

i bought the this item 2 clean my 20 gallon aquarium it doesn't clean d aquarium at all the water still remains dirty an i probably hav dis item about 1 week now an the water level is already falling slower than usual to me i find dis product is a waste of money an the tube that goes into the tank is so short it barely goes into the tank 3 inches properly