Hi all,

I am having problems with the reading from my KH director.

The readings are consistently low, KH director is 6.3, Hanna checker is 8.68. I have also check with Redsea manually.

I previously had the KH director attached to my profilux 3ex and it worked fine as far the readings compared to the hanna.

I have now swapped the 3 over to the 4.

I have recalibrated the pumps multiple times, remeasured the tubing and have double checked the tubing calculator and have also measured what is in the supply line.

Have also recalibrated the ph probe multiple times and have confirmed the calibration reading back in the solution.

Have also flushed unit, vented regent etc. The regent tube is well under 70cm and has no visiblefile.jpgfile1.jpg bubbles.

Pics of setup and control centre.

Anyone got any ideas on whats going on?