I dont think a NANO will ever need a chiller, Rather a cheaper way to chill the water are the blue Reusable Ice packs for coolers, and depending on how well it does you can gauge what size you put in the overflow area. Steve at Horizon Aquatics has the full setup with a good deal on coral attachments. Its nice and a comfortable way to acquire the complete setup and have a great place with good advice. Try to convince him you want his mettallic mushroms. LOL