I have recently purchased the Profilux 4 (Ultimate) and am very happy with the functionality that I have been able to use so far (the Touch screen can do with a major upgrade: the resolution of that screen is very 1990s :-)).

I am however having a problem getting the Profilux to control my two Tunze Stream 6055s in my 250 liter reef tank. I have connected the Tunze 1 and Tune 2 cables to them and these cables are in turn connected to the Y splitter which is then connected to the L1/L2 port on the Profilux. One of the Tunze streams is a more recent one and has the Turbelle controller to which I attached the Tunze 1 cable at the top and set the controller to "outside control". The second stream is an older model without the controller and I just connected the Tunze cable directly to the little breakout box.

I have assigned the 1-10v ports 1 & 2 to be Stream Pump 1 and Stream Pump 2. I also changed the voltage (after seeing other posts about this) to min 3v max 8v.

I then assigned Pump 1 and Pump 2 to Stream Group 1 with a minimum of 40% and maximum of 80% for each pump.

Here is the problem: the pumps seems to be constantly at the same speed all of the time, no matter which mode I choose. Even choosing "No current" (which I assume to mean that they should be off) doesn't change anything. When I unplug the Tunze cable 1 and Tunze cable 2 from the Y splitter, the pumps keep working at the same speed.

I tried to move the Y splitter to the L3/L4 connection on the Profilux. Then both Stream pumps stopped working!

What have I missed?

Any help would be appreciated!