Are 2 250 watt XM's not enough?

[Derek B]

I have a 4' long 24" Deep 65 gallon tank and I read a thread on Reef Central that said XM bulbs do not have enough PAR to sustain SPS long term??? Could this be true???

On another topic, I need some opinions ..

I am going to add 2 4' VHO bulbs to my setup. Knowing that I have 2 250 watt XM's, what 2 color spectrum VHO bulbs would you get??? Forget what it will look like to me .. .I want opinions on what will be the best combo for superior coral health. This will be a good topic for the meeting next week :D

[captexas]

I have a 75g myself (4ft long and 21in. deep) with two 400watt 20k XM bulbs and two 46.5in. 110watt VHO bulbs (1 is a 10k and 1 is actinic). I like the way it looks and my corals are doing fine. My SPS growth may not be as much as others and definately no where close to Jim Norris! The 10k XM bulbs are supposed to have far greater PAR than the 20k lamps, but they will be much whiter in the way they look. If you go to the meeting at Jim's, you will be able to check out both of them in person.

[manny]

hey josh, what kind of T5s are you runnin?

[Derek B]

Cap, I was thinking of doing a 10K and an Actinic as well. Actually, I thought of doing a 65K and an Actinic. As far as the XM's, I love 'em. If I got the 10K XM, I would definitey do 2 Actinic VHO's. That would probably look pretty sweet. Have you seen a 10K XM in person or heard any testimonials on them???

Josh, I heard that the Corallife bulbs are much better than URI and tend to last longer. What is your opinion on that???

[captexas]

Derek -
I have yet to see the 10K in person, only pics Jim Norris has posted. Hopefully I will be at the meeting and can see them in person. The par value is supposed to be much higher than the 20k and even higher than the Iwasaki 65k. As far as the VHO bulbs go, I have heard that the Coralife bulbs tend to be pleasing to the eye, but not as accurate as for what they are rated. I have only used URI bulbs so I can't say for sure. I do know that most of these companies simply buy their bulbs from other large manufacturers and have them private labeled.

[captexas]

LOL, I was thinking about just using actinic bulbs to supplement the halides, mostly so I could just turn them on and see all the cool green corals! :-) But I figured as everyone seems to think the 20k XMs are too blue I didn't want to add to the problem. Right now I have a fairly nice balance.

[manny]

I'm thinkin bout goin the 10K route, but I like the glow of the actinics and I like the fact that I can do a morning effect by just having the actinics come on and about 45 mins later have the MHs come on

[Instar]

Derek, I have a URI VHO bulb, 48 inches long that you can have to get you started. Its new. I needed a NO and they sent me a VHO. Don't recall if its 10K or actinic. I'll let you know, if you say you want it.

[Instar]

BTW, I quit using URI when I found out the bulb life was so short.

[captexas]

I believe VHO lamps have the shortest live span between VHO, power compact, and halides. Usually recommend replacing them after 6 months of use. I think PC lamps have to be replaced after about 9 months and halide lamps vary.

[SueT]

Jim sold me on the XM's and I am now using 3 over my 180g sps tank. JB NY on RC did a lighting study that shows the X<'s are on 2nd. in PAR to the iwasaki. To me that says they have more than enough PAR to keep sps happily. Here is the link to that study: http://www.cnidarianreef.com/lamps.cfm This shows a lot of different 250w lamps run on different ballasts and the PAR reading each had.

I am really loving mine and I am now seeing coloration shifts that are for the better. My purple plating montipora is a purple/pink that the colors jump out at you. It is amazing.

[SueT]

Joshua, I'm definitely using the 10k XM's. I was afraid the 250w 20k XM's would be too much of a PAR loss from the iwasaki's. I was so happy to find out the 10k's are as high in PAR that things might not suffer. I also supplement them with 2 160w URI 03 blues. Shame on me as they are nearing 2 years and I have them on the list to be replaced next. They still kick a lot of blue out though.

[Derek B]

Thanks for all the input guys!!! I did not realize how much punch (PAR) I had lost going from the 65K Iwasaki to the 20K XM. I think what I am going to do is burn my 20K's for the remaining 6 months they are good for and then get the 10 XM's with 2 Actinic VHO's. That color combo looked the best of all in the study that Sue mentioned.