Does anyone use the Danner model 7?

Okay... With some resistance, the model 3 & 5 perform quite similar. But, the Model 7 goes well beyond what the others can do. Would the extra flow (head) outwheigh the added heat generated by the pump as it consumes double the electricity of the model 3?

Dunno, depends on how you plan to use it. I've been pretty happy with mine running it inline in an external box, and haven't seen any significant probs. If running submerged, I'd go with the MD3, though, since the MD7 does get a little warm to the touch.

Define "warm to the touch". Does this mean you can't hold your finger on it for prolonged periods or does it merely mean it feels a LITTLE warm?

I believe Cathar talked about this exact situation before. I will try and find what he posted.

Ah! Here's the link to Cathar's comments:http://forum.oc-forums.com/vb/showthread.php?s=&threadid=184315&highlight=danner+cathar

For those of you who are lazy....

"Looking at Les's graphs, and then looking at the pump's power consumption (and therefore potential heat dissipation by the pumps into the water), I would say that the best pump for the job is clearly going to be the model 3.

When it comes to pumps, then unless you have a very specific scenario such as pushing up a high evaporative tower, or experimenting with super-resistant blocks - the White Water not even beginning to fall into the category of super-resistant, then bigger pumps are almost always overkill. The extra heat that the dump into the water almost always overwhelms the minor benefits seen by increasing flow-rates (especially past the 2gpm mark), unless you're using a stupendously large radiator or a number of them (as in like 4 D-Tek Pro cores with high speeds fans or an equivalent).

Pump heat is pretty much the single biggest barrier to obtaining improved performance beyond what pretty much any 1.5-3m pressure head pump will provide for you."

Wow! Good answer! Thanks.

I ran a both a Mag 5 and a Mag 7 with the Danger Den MAZE 2 and 2.2 series blocks. The Mag 7 was better by a couple of degrees. The 1200 and 1800 GPH Danners were a different story, much warmer. Your results will depend on your particular system.

One more thought. The Mag 5 and Mag 7 are the same pump except for the impeller. For a few extra bucks you can buy a second impeller and try both configurations in your system.

I ran a Danner 700 for awhile and it was pretty noisy and got pretty warm (compared to my Eheim). But worst of all it started leaking, first from the seam of the cover and unit, but then it just started leaking from random places, like pinhole leaks. I tried to seal it with everything imaginable but it got worse. I finally gave up after lots of headache and got the Eheim 1250 that I originally wanted. To make it worse, the first Danner 700 I got was bad right from the start, this was the replacement!

It did perform pretty good though, it may have been a bit overkill though. I didn't see any change going to the Eheim. The setup was a Maze2 and a DD Cube.

-Rav

Shroomer said:

Define "warm to the touch". Does this mean you can't hold your finger on it for prolonged periods or does it merely mean it feels a LITTLE warm?

Click to expand...

Just a little warm, certainly nowhere near enough to cause discomfort. Although I never took any kind of temp measurement, if forced to provide an estimate I'd guess maybe 5~10 degrees F above body temp.