I'm only running the two darkest blue LEDs during the evening and have just turned them down to 3% for a couple of hours after ramp down so that we can see something in the tank while we're at home. I've now turned them off all night after that. I wasn't running the full spread all night long (6 colours in the AI Vega). Thanks for the tip, I have been doing that and it seems to work well. I've managed to get the specific gravity up to 1.025 with the slow salt top up and will double check tomorrow with a salinity tester I'm going to borrow. My levels (Ca, mg, etc)went down over the weekend as I was out of town and wasn't dosing but have done another 5G NSW change and have another 5G NSW ready to go. I may do that in a couple of days, maybe two 5G per week is a good target. I'd love to work out how to get this stable although all I can see so far is LOADS of water changes, maybe that's the key as has been mentioned several times. Anyway - I'll work on the salinity first and see if I can get that stable and where it should be with fresh top off and will probably switch to salt mix soon enough.