I just recently started up a 15 gallon fuge with a 135 watt PC fixture. I don't know if that qualifies as high light as it's only PC, but so far so good. It's been running for a week and my gracillaria is growing visibly almost daily, while the chaeto appears to be growing at a slower rate. I don't have anything to compare it to, though, I haven't run a fuge before this one.