MH Bulb Combinations - 175W

[SI_rEEfer]

I have a dual MH hood and I am considering using two different MH bulbs to improve the intensity while getting the color I want. Specifically I am considering using an Iwasaki Aqua2 15K and an 20K bulb, possibly an XM20K.

Currently, I am using a pair of 175W XM15K bulbs and I also have two 96W power compact bulbs (1 actinic 03 and 1 50/50). I like the color of this combination but I would like more intenisty.

My question is, can this be done without it being the first thing you notice when looking at the tank? I would like it to be subtle.

I have read post where individuals with larger tanks will use 3 bulbs. A 20K in bewteen two 10Ks.

My tank is a 65gal, dimensionally 36" wide, 24" high and 18" deep. I am using a standard dual 175W PFO M57 magnetic ballast. I keep the lights ~ 10" above the top of the tank. The hood is a 36" long PFO. The MH bulb sockets are located ~ 6" in from the outside ends of the hood and the bulbs are screwed in so that they are nose-to-nose with in another along the same axis. This leaves ~6" between the bulbs.

If anyone is using two different MH bulbs above their tank and has pictures they could post that would be greatly appreciated.

I am also considering using a pair of 175W 12K Coralvue Reeflux bulbs.

 

[raynist]

I think if you went with 2 of the Iwasaki's and then make both of your PC lights actinic you will be very happy.

The Iwaski is SO bright and so white that I think it would really be noticeable next to a 20k bulb. The iwasaki will most likely be 2 or even 3 times the par of the 20k bulb.

--Ray

 

[SI_rEEfer]

I just noticed on Sanjay's website that the PPDF for the 175W Iwasaki is 71 vs. 51 for the 175W XM20K (on an M57 ballast). This does not seem too disimilar.

Would you expect them to look visually disimilar in intensity?

It also looks as though the XM20K has more PPFD than the XM15K, 51 vs. 39.

How blue are the XM20K's by themselves? Anyone have pictures of tanks with the 175W XM20K driven with a M57 ballast in their gallery.

 

[raynist]

<a href=showthread.php?s=&postid=8998149#post8998149 target=_blank>Originally posted</a> by SI_rEEfer
I just noticed on Sanjay's website that the PPDF for the 175W Iwasaki is 71 vs. 51 for the 175W XM20K (on an M57 ballast). This does not seem too disimilar.

Would you expect them to look visually disimilar in intensity?

It also looks as though the XM20K has more PPFD than the XM15K, 51 vs. 39.

How blue are the XM20K's by themselves? Anyone have pictures of tanks with the 175W XM20K driven with a M57 ballast in their gallery.

That is pretty good for a 20k bulb. It may only be 20 PPDF which might not be a huge difference if you are talking the difference between 400 and 380, but the Iwasaki is putting out 40% more light. That will be a big visual difference in my opinion.

--Ray

 

[SI_rEEfer]

Thanks!