I have two A360Xe's on my tank for the shimmer (along with three XR15G6) so I like Kessil & their app. I have an Innovative Marine EXT 200g Peninsula & bought IM's ChaetoMax light. You cannot control any spectrum with that light. It is very basic & small & the only control is on/off. I got a hunk of algae from LFS about 2 months after cycle, a mix of Cheato & Caulerpa. Within 3 months nearly all of the Cheato had slowly turned brown & died, except one tiny ball in the corner when I decided to upgrade to this light. I researched using it beforehand & read that the full red spectrum of this light grows Chaeto like mad. And let me tell you, that is 1000% true! Within a week, the Caulerpa started dying off & turning brown around the edges, & the little Chaeto ball had more than doubled in size! I let it go, pulling out the brownish Caulerpa every day as the Chaeto ball got bigger and bigger. One month later, all of the Caulerpa is literally gone & the entire refugium (16 x 18) is completely full with deep green colored Chaeto. I expect to harvest some of it out next week as it has completely packed the entire refugium space. Not sure of all the bad reviews, this light is working perfectly for me. I have it on 18hrs & off in the middle of the day for 6hrs full red spectrum 100% intensity. I have it mounted 9 inches above the water line with the Kessil 90 degree mounting arm. With the reflector in place (it comes with it) the spread is the perfect size to fully cover the refugium space. IMO, you cannot go wrong with this light if you are looking to do Chaeto in your refugium.

So I was happy with the light, having it in my refugium with no problems... did a short schedule and everything was great.. until the unit would randomly shut down completely, after further inspection I realized the unit overheats, telling me the fan was shot, to further my correct diagnose, I left it on manual at very low power setting and it would stay on, no problems. I contacted kessil and they wanted $100 to tell me what was wrong with it or give me a discount on a brand new unit... dude.. I paid over $500 for around two years of service? And now I'm stuck with a unit that cannot be fully used because the fan is not available anywhere else and they "cannot sell me that part" even after I explicitly told them that it's cool if I void their expired warranty and that the repair is a 100% on me. The problem is salt creep in their fan unit, the fan unit is a third party manufacturer, the coating they use for their little board is not of very good quality and it fries it. Well, let this review be of help to you when making a decision.

I'm not sure why. had several Kessil H380 lights and My LFS could never believe how much chaeto i grew and brought them. Unfortunately, those lights burned out and I got the 360x's who's spectrum looks different (despite what the web site says it is) and my chaeto has never grown as well....don't know why, but Im disappointed.

Switched from h380 to gro to this light h380 was way to much and I could not raise it anymore the gro was awful this light is expensive but you get what you pay for it you can adjust it and it runs extremely cool I love it highly recommended

This light has done a good job growing Chaeto. My nitrates plummeted to zero so I cut back the duration of grow light time and I had to start dosing some nitrate to keep my corals happy. My reactor handles the phosphates. Overall, my reef water quality is greatly improved by growing Chaeto. A big con is the insane expense of the light so I would decrease the overall rating to a 3.5.

I'm very happy with the performance of this light compared to my old kessil refuge light. This thing is growing chaeto like a champ. I'm pulling out basketball sized clumps every week. Even had to start dosing nitrate because of the growth. I should scale back the intensity to prevent this, but it's easier to dose nitrate to where I want it than experiment with light intensity which takes days to see. Either way, I'm super impressed.