Confused about lighting...

[Lareina&Mike]

Hi all,

We have a 30 gallon tank (30"x18"x12") and we currently have 2-8W T5's which isn't much as far as I've been reading. I've been researching a bit and thought if we got 2-24W T5 HO's it would be enough but now I'm doubting myself... We have some soft coral frags we just got (2 mushrooms, 1 clove polyp and 1 candy cane coral) and the guy at the LFS told us as long as we had a T5 we'd be fine but now I'm getting conflicting ideas from what I'm researching about how many watts are appropriate. Does anyone have any tips on lighting? We'd love to get an anemone some day as well but I'm pretty sure we'd need a lot more light before we do that... Please fill me in!!

Lareina

[thegrandpoohbah]

That Candy Cane is a large polyp stony (LPS) coral and will require moderate to high lighting. On a tank that size I'd be going with a 4x 24W T5HO fixture with 2 10,000K white bulbs and 2 actinic blue bulbs. With that light set-up the ends of the tank will be a little darker because even a 30" T5 fixture still uses the same bulbs as a 24" fixture. If you don't mind a bit of overhang then get a 36" fixture with 4x 39W bulbs. The other thing to consider with T5HO fixtures is the quality of the reflectors. A high quality unit will come with indvidual parabolic reflectors which put more of the light into the tank versus a cheaper fixture with the same number of bulbs but cheap reflectors.

[bosshog]

The only time you can have enough light on a reef is when your bank account runs out of money for lights and electricity.

Just kidding.

2x8w t5s is woefully inadequate for a reef tank. thegrandpoohbah is giving the same advice I'd give you.

Stay away from cheap t5ho's. Make sure you get the ones with the individual reflectors. If you can't afford them now save up and buy them later, good reflectors make a world of difference in fixtures of the same output. Good lighting is getting less exspensive all the time.

Another consideration is what do you want to keep in the tank in the future? A softie tank will generally have a lower light demand than an SPS tank. Do lots of thinking and research before you plunk down your money. It will save you some expense in the future.

Edited April 29, 2009 by bosshog

[kem]

I've played around with lights in my reef tanks, except for the pricy LED, and in my experience, nothing beats metal halides. The soft corals are responding very well in terms of growth and expansion, and I've never seen my fox coral opening this much.

If you can afford the cost and the utility bills, you could have a 150W MH, centered and about 10 in. from the water surface. It will give a nice coverage and leave shaded areas on the sides for less light demanding corals.

If MH are not an option, your next best choice is HO T5 with individual reflectors. I'm currently keeping SPS and a clam in a 20G tank under 4 24W HO.

Whatever option you choose, be sure to search the need of the corals before buying them. Placement, flow, supplements and potential feeding are also critical to success with corals.

Here's a link that I find very helpful : http://www.wetwebmedia.com/marine/index.htm

[zooz]

What would you like to keep in the future? When I started my first tank I just had compact fluorescents and inevitably I fell in love with SPS and had to upgrade my lights. I would suggest something stronger than what you have. T5's with individual reflectors are also great. That way you can save money in the long run if you decide to keep corals that require stronger lighting. :thumbs:

[MMAX]

It also depends on how deep your tank is. With your 18" deep tank you can get away with T5s even for clams and SPS. If you get a 4 or 6 bank T5 hood and don't plan on upgrading to a deeper tank down the road you'd be fine.