180 gallon lighting

[yanek]

I'm planning a tank-in-wall setup and as yet have not decided what size tank I'm going to have. Either a 120 or a 180... cost will play a factor as always. And one of the cost factors is lighting.

I have a 75G right now with 4 96W PCs, two super white, two actinic. Haven't tried the smartlamps yet. They seem to work well with this tank... i find the light a little diffused (less ripple-shadow) which is a shame, but I'm supporting an anemone on the bottom of the tank and frogspawn, monitipora, and whatnot.

I clearly need to support the same fawna in the new tank and don't want to rule out clams from my future.

My immediate thought is that I could keep one ballast for actinics, running them in one long strip across the tank length (will be a little overlap on a 180, mostly overlap on a 120) coupled with MHes. Two for the 120, 3 for the 180. At least 350W a piece. I saw an article here http://aquarium.union.rpi.edu/articles/DIY_MH.html ... but can't corroborate.

Thoughts? comments?

 

[yanek]

Well I'm still confused on this. I've been reading and reading and having used PCs for 5 years I still don't get all the differences in MH bulbs. I don't want to spend an arm and a leg if I can help it, and it looks to me that I will need at least 3 400W MH bulbs and perhaps I can use a pair of PCs that I currently have for the actinic blue.

So the question is... what kelvin rating am I looking for in MH bulbs? I know this is somewhat a matter of personal preference. I now have a pair of 10k coralife PCs and a pair of 7100k actinics. I like the color. Would three 10k MH bulbs and those same pair of acitnics do? What about the KIND of MH bulb? There are single ended, double ended... "reef star system," etc. It's all quite confusing, I feel. Help me out

 

[fishfreek]

How on earth did this post get lost? Im very sorry that no one replyed when you first posted.

I clearly need to support the same fawna in the new tank and don't want to rule out clams from my future.

A 6' long tank will indeed need 3 MH bulbs. This is because MH bulbs will light an area of approx 2' sq and beyond that the light intensity really drops off. 250W bulbs are good for tanks at a depth of 24" or less and tanks deeper than 24" can benifit from 400W bulbs but you could get buy with 250W if you put the light needy corals at leat 1/2 way up the tank.

The kelvin rating for MH bulbs and their ultimate color can be different based upon the brand of the bulb. Its very strange to see two bulbs both that might be rated at 10K and they have a very noticable coloration difference.

Here is an excellent link to a study done showing just what I describe above.

http://www.cnidarianreef.com/lamps.cfm

There is also detailed info on different ballasts aswell.

 

[yanek]

What a great link; I'll check that out. I'm starting to talk to contarctors how about doing the dirty work. I'll probably go 3x400W plus a pair of SmartLamps.