I've seen Tunze's "reverse and clank" per say when they are not getting enough water flow or are struggling hard to get it. For example, if you take your hand and cover most of the input.
Is it possible you have them all cranking way too hard, and they're not getting water into the back area fast enough? Think about them turning into a true pump, where they have to forcefully try hard to draw in enough water. Try running them on low, and see if you can reproduce the issue. Personally, I can't possibly fathom you having 5 of 6 bad Tunze's based on my experience and reputation. Something has to be wrong...
It's not that they are not getting enough flow because when all 3 on one side were set to full blast the water level was only like 1/2" lower then the tank... I have take them out and tried them in the bathroom upstairs in a bucket of water... Also I have them on two different controllers (1 controller per side) and I have them set from 40-100% alternating so all 3 pumps would never be running at 100% per side... I have tired to turn them down and trying to run them without the controller I have tried everything, like I said I spoke with Roger and he was not able to come up with anything I hadn't already tried... I also find it hard to believe that 5 out of 6 pumps could all go bad, that is why I would like to find out what could have caused it so it can get fixed... They are still under warranty but I don't want them replaced just for it to happen again... They were running fine for about a month and then all of a sudden they started dropping one by one...
It sounds like a power issue to me, with them running backwards. The Tunze Stream pumps have small brakes on the impeller near the top of the magnet to make sure it doesn't spin the wrong way.
Have you tried running them without the controller? If they all work properly with Power (120v? ) --> Power Supply --> Driver ---> Pump then the problem could be a setting in the controller.
The older impellers have "brakes" to stop them from spinning backwards... I guess the newer controllers are smart and will not allow the pumps to run the wrong way...
Rogers goes over this in more detail in this
thread
I have tried running then with out the controller(s) and I get the same thing, as soon as they are plugged in I get the alarm...
On the electric side of it also are they plugged into some thing you wired? If so are you sure you wired it correctly, because if you wired a outlet wrong you could also get reverse polarity.
I would have to agree with Rokel and say that it would be hard to believe you got 5 bad Tunze.
I also did the Siphon break with back flow valve on my returns and put in two emergency over-flows in my sump that go right to my sump pit in the basement and pumped out to the street.
BTW I have seen you mention other tanks you have in your thread, you have any pictures of them you could share, would love to see them.
Yes they were, but I have a tester and they are fine and were fine for over a month... I have tried running them on other outlets and get the same response...
I will be looking into an emer overflow drain near the top of my sump very soon... I will also be picking up a full house gen alot sooner then I had planned...
I agree with RokleM. Reduce the pump output to the minimum to see if that fixes it. If it does, than your inlet's for the overflow box are undersized.
The Tunzes will not even work outside of the "Tunze box"... As soon as I plug them in I get an alarm and I have cleared them, let them soak in vinegar, used different alerts then what they were plugged into for a month before they stopped working... I just don't get it... If I play with some of them enough I may get it to spin for a few sec's but it's jerky and the alarm chirps because something seems to be dragging and the only thing that it seems like is the impeller is spinning backwards and the brakes are slowing it down...
Anyway...no reply needed. This is your thread. I just wanted you to know that I share your pain!
Untamed12, thanks for your post and I am sorry to hear about your losses... I had a clown in the 50gal frag tank and it was fine, I have since moved him back to QT... I still have 6 shrimp (3 fire and 3 cleaners) in the display with a few pep shrimp in the frag tank that are doing fine, along with prob close to 550 various snails throughout the system... The snails are even laying eggs...
I have only been running the MH over the frag tank (since I have a few corals in there which are doing fine), the macro light (24/7) and 2 of the 4 MH's over the tank and will keep it like this until some time in March when I might try to add a few small cheap fish to see how they do...
Drill a small hole on the underside of the Locline (just under the surface of the water), in an area where it won't splash. This will keep a common siphon break regardless of how you position the output.
I saw this done a few times, and Melev's site comes to mind as I believe he talks about it and has some pics about it... I will be doing this in the next few days...