There were simple instructions, there was not enough information. Scanning the QR code for more information brought me to a product page for a filter designed for a 50 gallon tank. I checked the brand's website for more information and there is no mention of this little tank. It also arrived broken. The lid is not secure because the piece of plastic arrived broken (it was floating separately in the box. When I asked for a replacement (they ask us not to send it back via Amazon) they responded but never sent a new tank or one refund offered.