I've had my used light since Feb. this year, started buying 2 crocea clams and acropora frags soon after. They are growing more on the base so I think all is well. How do I determine which bulbs have what PAR? Found some cheap on ebay and someone said the Par is horrible. So how can I know what bulbs are better than others? Came with blueline 10K i think, and bought a 10K XM off ebay.