A reasonable amount of experience.... except for lighting

[GBRLocal]

Hi All,

this is my first post on the site, have spent a bit of time looking around and I am amazed by the level of knowledge on tap.

I am not certain if this question belongs here but here goes...

I have kept fish only / fish and live rock (with a few bits of hardy coral) for a while and for the last year a nano tank with assorted corals and two damsels (2 foot tank). The thing is though the bug to go bigger has bitten me and I am going back to my orgininal tank. Trouble is that the lighting in the stock tank is inadequate for most corals I am interested in these days. My nano szed tank is running a 150w 14k MH and doing well. The issue is that I know that one 150w lamp is not going to be sufficient for a four foot tank (Nor are the two 30w flouros in the stock hood...). I am unable to purchase another 150w lamp to run as a pair (money is tight at moment) but I do have access to a number of 70w MH light ballasts and sockets for free (or a case of beer.....) from a friend in the building industry. (all lights would be running 14k globes)

My Question is will 4 70w MH's be suffiecient if run equally spaced along the tank? The tank is 20inches deep. I am looking to keep mushrooms, xenia, a green carpet ananome that I have become extemely attached to and generally the run of the mill easily available corals.
Will supplementation with Fluoro lights help?
Would there be any combination of four 70w and 1 150w that could be used?
Another 150w lamp or greater is not an option at present.

Your help with this will be most appreciated

P.S. Sorry for the really long post.

 

[mg426]

If you can get them free I would give it a shot for sure. 70 watts is not going to penetrate so good though. Mabe put the 150 on the 4 footer with a couple of 70s . Keep the corals up on the rock work a bit.

 

[bertoni]

I would also make sure that you had good reflectors, otherwise, the efficiency will be low. The problem there is that reflectors are expensive. I suppose you could try the 70 W fixtures, but I'd probably go for 175 or 250 W setups, depending on the exact tank size.

 

[GBRLocal]

yeah, I kind of thought there may be light penetration issues. I guess with a bit of carefull planning of the tank layout and coral positioning I may be able to set it up so that the 150w is over one end have the more light dependant species there and at the other end under the 70w lights have a kind of sand "plains" area with a few bits of live rock and very low light tolerant species. A bit of swimming space for want of a better word?

 

[GBRLocal]

Thanks for that Jonathon. the tank itself is an Aquaone HR1280 set up which is about 120cm long, 46cm wide and about 50 cm deep. (sorry about the metric but being and Aussie its what we deal with mostly)

As I said before my friends back shed has all sorts of fittings and fixtures in there so I wont know for certain what I have available to me until I do some digging around in it and a bit of bartering...

 

[bertoni]

That tank is deep enough that you might want 175 W bulbs to grow light-demanding organisms at the bottom, but as you've mentioned, if the corals are chosen and positioned carefully, the 70 W should work.

 

[GBRLocal]

Yeah, this might be an excuse to take a week off work and head for the reef and spend a bit of time out of my boat in the water taking notes of what grows where in nature!

Based on the lighting combination I may have to work with I have been comtemplating a reef "ledge" and "plain" idea. That would also allow a bit of open water for fish species that dont just hang out in the rock work. Either way when I move house in a couple weeks and start setting up the bigger tank I will be documenting the setup as I build it just for my own records. (Being an Environmental Officer for a large coal mining company means I am used to documenting everything!!!)