Im still running my original 6025, the one with the flat cord. Been doing so since march. The first time i tried to clean it i broke the 2 lower clip that attach it to the magnet. I really like the flow better than my Korolia 4, not comparing gph. The only real problem i have with it is that the impeller sometimes stalls when i restart the pump. I usually just jam in my stainless tweasers to give it a little push start with no ill affects.

I've really been tempted to try out a Koralia to replace my 6025. You mentioned you like the flow better on the nanostream. How is it different?

From what ive seen of the two the Tunze 6025 shoots out more of a cylindrical stream whereas the korolia 4 is more of a cone shape (almost shoots out in a 180 degree angle from the impeller) and does not travel as far. In my case, a 20g i didn't want to have more than one powerhead so the tunze won because it could penetrate deeper and created less dead spots in my tank (i still have a few im fighting with). Maybe you could up the size to a 3 or 2, but i had corals too close to the powerhead that couldn't handle the flow.

nanos
 

Are these mainly with the 6025s or with other models such as the 6045s and 55s?

The problems you mean? Unfortunately, these occur throughout the entire nanostream line.

I have been running 4 6055's on a multi controller for a while now. I have had no problems with them so far. It is still a toss up to me though wether they work better all running full bore with out the controller, or if the random alternating flow is better.

6025 and 6045
 

I went through several pumps...had all my original 6 replaced...and all the replacements broke too..the impeller shaft snapped off (rusted) at the base.
Also had at least half of the c-clamps break...finally gave up and traded up to 6100's and a controller...needed more flow anyway...but I think there must be a design flaw with the nano's..Karen

Tunze pumps
 

I've got 2 Tunze 6100s and a nano 6055. All variable speed, which makes a huge difference in the tank (e.g. they slow down at night and are programmable for storms, surge, waves, etc.).

Expensive, but well worth it. One thing not mentionned on this discussion is the fact that their transformer units are outside of the tank, keeping heat exchange down.

You may want a 7095 multicontroller if you've more than one Tunze pump. I've got one if you're interested (see for sale section).

I've been running my pumps for more than a year without a hitch. They can be noisy when they surge to 100 percent, but it's usually vibration and can be corrected by shifting the pump position.

Cheers,

Erik

http://www.reefcentral.com/forums/sh...readid=1025361

I've been running a 6025 and a 6045 for a couple months now. I cut them both up as soon as I got them, and haven't had any problems with them since. They were both purchased after september 07 and both have the round power cords.

One of them started in reverse for me once, I put my hand in front of the outlet and the prop started spinning the right direction right away.