The Seio 2600, while it did move tonnes of water, is huge. Imagine putting a size 7 shoe in your tank. That's about the size :razz:

I tried a Tunze 6100 out. Beautiful piece of equipment, but I do wish they would develop a better mounting system than those cheapo plastic bits they provide.

Don't they have magnetic holders?

The size isn't a HUGE deal, because I can hide it behind rockwork that is shaped into a circle through which the powerhead will just poke out.

Is the Seio 2600 significantly larger than a Tunze 6100?

I have magnetic holders for one of mine and the other jerry rigged with their cheap comes with mounting hardware - get the magnets - haha... If you REALLY want to hide them in the rocks they offer a specially designed rock to all but hide the whole powerhead... Ruth is right about the controller - the non controlled Tunze and Seio's DO provide a really nice flow, but you put a couple of Tunze's and/or a wavebox in and the variety of currents and flow patterns is absolutely ENDLESS... there just is no direct comparison to anything else, I've seen some pretty tricked out closed loops on Ocean Motions and Sea Swirls, I have two CL on SQWD's myself, (now used primarily for surface agitation), but nothing, even at higher outputs, will create these natural currents in your tank like Tunze... they're simple, well built, and yes, expensive... but after going through the Maxijet-Seio curve, I will never go any other direction when it comes to moving water in my tank and making waves... of course they may be a little extreme for a 20g! :mrgreen: