10% seems to be the best sale you'll find. I think the mark up on alot of reefing equipment is actually fairly low, so companies can't have huge sales or they'd be losing money. They had a 10% off sale for black friday last year and I got my apex then. I went full apex, but probably would have been fine with EL. Salinity is nice, but I read alot of people have issues with it reading consistently, and ORP isn't generally the most useful parameter to monitor-but why not? I can tell when I feed my coral (ORP drops) and i have dosed peroxide a few times and see it change too. I've yet to use the ORP value to do anything useful though.
I just used this sale to get a trident, and am super excited. That's the main reason I wanted an apex in the first place, bt couldn't spend the money on both at the same time.
If it makes you feel any better about spending the money, Neptune products maintain their resell value really well. So if you ever decide you don't need or want it you can surely sell it for not too much of a loss. That's not the case with alot of equipment.
