http://www.advancedaquarist.com/blog...rbulence-video
ok gust some comparison, I know there is some data telling Tunze is below there reading, however I have to agree with what the video shows.
the Tunze is more under pressure vs vortech, resulting the tunze pumps whatever flow thy have, clearly shows that that flow makes it to the other side of the tank.
the votech on the other hand has more flow as thy claim, but this flow shows clearly to disappear as soon as it gets resistance from present water in the tank.
comparing it with a needle ore a stump point, I know what makes it further into something.
thing is that compare it with a long thick rod (the stream of the tunze) all the surface of that rod is moving one direction, creating friction with the surrounding.
meaning that if the pump is rated for 2000 gph, it in fact can move much more, because the stream itself creates friction / turbulence
the vortech next to it is the stump point that looses its power under its own power, and as a stump stick in the grown, it will go in, but only if you keep pushing, ore in other words, the votech needs to run longer to mix a tank than a Tunze douse.
for the information, I don't have a tunze nor a votech, I don't criticize any findings, but this at this time is how I would se the entire comparison