The cheapest solution is to replace the existing AI fixture and unless there is something you really don't like about them. Why incur all the expense to replace them? It's may be worth sending it in to see what it might cost to repair also. Is it a Prime 16HD that you need? If so PM me, if nothing else you can borrow one of mine until you come to a decision on what to do. I don't buy a Gen 1 anything and the Neptune is using the Phillips coral care design, so both of those are a wait for the Gen 2 release as far as I am concerned.