Hydor isn’t one to sit back and let Tunze recent nano streams to take over the nano market in water movers. So what do they do? Offer a “nano” version of their Koralia pumps which pushes a measily 240 GPH. However, you could purchase a Tunze Nanostream 6025 that pushes 660 GPH for about $65 through your local fish store or online. Which would you pick?