Thought I'd share my days work (well a couple of hours) with you guys since its GHL related. I've converted my Geisemann light unit to dimmable T5 ballasts that I can now control with my GHL.

I first stripped one side of the unit down and found it all looked fairly simple.



Gave the existing Phillips ballast a tweak and it was just stuck to the inside of the case with some blobs of silicone and came away with some gentle pressure.



So I stripped both ballasts and wiring out of both sides. I removed one of the 3 power leads as this was no longer needed. The remaining wiring is for the halide, the power lead that will be connected to the new ballasts and the control lead for the GHL which takes the place of the removed lead. I had to remove the lamp holders too but these will be re-clipped in place later when wired back up.



Stuck the new ballasts in exactly the same way as the old ones with a couple of blobs of silicone and then left it for a few hours to go off enough to start wiring.



All wired back up including the EVG-AP-2F. Most of the wiring was reused just had to add a few new bits as the wiring for the new ballasts was slightly different and also had to add some extra earth straps for EVG.



All back together and tested working perfectly. Quick wipe down and it was back over the tank and sat playing with cloud simulations etc