About this item Well for 42 inch Long Fish Tanks — Calculate for the rectangular tank: (42” L x 12” W x 19” H)/231=42 gallon, our water chiller can drop water temperature up to 10F in general. In hot summer, recommended water volume is 80%, 33 gallons. Upgraded Accessory — The new water pump features a stainless steel shaft, thicker wires, and American standard plugs. Additionally, two types of water pipe clamps have been added to help you secure the water pipe in the fish tank, making it look more beautiful and less likely to blow up sediment at the bottom. Essential for Hydroponics and Aquarium — High-efficiency freon free compressor provides more rapid and stable cooling than small fans, using r290 refrigerant, circulating cooling without pollution and do not need to be supplemented. Can well control the ideal water temp at 68-78F/20-26C, necessary for creating healthy roots and a good harvest Tips in Summer — The standard water volume is 42