I have this product purchased in September last year:
https://www.bunnings.com.au/maze-2-x-100l-minitank-kit_p0530114
It has been fine until a couple of weeks ago when the tap on one of the tanks started leaking from the top. Note that it is in the off position in the photo. It makes no difference if it is off or on. Would this be a tap fault, or is there something I can do with it? Thank you.