MH vs. T5HO

Sploke

Sploke

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Oct 20, 2005
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I've read about this topic to death on RC but I wanted to get some opinions from people here. I'll be starting a 120gal system soo to upgrade my 55 reef, which has 4x55w CF over it now. I can't decide between 2x250w MH or 8x54w T5s. I will most likely be doing a suspended canopy from the ceiling.
 
What type of corals do you plan to keep. The T-5's can be setup different ways but remember you will get the full intensity the full length of the bulb.
 
Yeah, I've heard that as a bonus and a disadvantage. I currently have a few LPS and some softies, but I'd like to try some SPS as well after the upgrade. It sounds like the T5 is good because you have equally powerful light over the entire tank, but I've also heard people say that it lends a sort of "flat" lighting scheme to the tank, while hte MH, being a point source, gives the nice "shimmer".
 
I must admit I love the shimmer my MH's give on the sand bed. I have 2 x250w over a 5ft tank. I get a slight shadow in the middle (which doesn't tend to show on photos) but I think that also adds to the "natural" feel. Plus with MH's the world is your oyster (so to speak) and you're not restricted on what you can keep!!!
 
Having run both types for quite a while here is my conclusion:

T5HOs - Good for heat, dispursed light. Bad for how many bulbs you MUST replace every 9-12 Months as well as intensity. (My corals exploded in growth when replacing my 6 T5HOs to a single MH)

MH - Good penetration, much better PAR than T5HOs, bonus "shimmer" effect, same bulb replacement schedule, but only 1 bulb vs many. Bad for heat.

Depending on tank size would depend on my personal recommendation. 6 T5HO's on a 29G is fine, but when your looking at 8-10 T5HOs on a 75G+ tank then it gets expensive for ballast and bulbs.
 
Most places recommend replacing T5 HO bulbs every 12 months for actinics and 18 months for daylight bulbs... (normally driven, overdriven is 12 months even for daylights) This is the first I've seen as short as a 9 month replacement period suggested for T5 HO bulbs.

There's 5 T5 HO bulbs on our 90g (all with IceCap SLRs), 2 normal driven / 3 overdriven, and there's no issues growing anything from mushrooms and zoas to open brains and acans to Montiporas and Acroporas in our tank. It's all about coral placement. Can I grow SPS in the upper half of the tank, certainly, but not so on the sand bed. But, there's a clam just off the sand bed that's doing well. Generally, I don't see much for limitations when it comes to T5 HO lighting that's done right. I could add a 6th bulb and have more flexibility, but there's little need for it considering what's currently in the tank and the results I'm seeing. If I wanted some of the higher light Acros, I'd have to install a 6th bulb, but those aren't something I'm into at the moment.

I'm not sure where 8 - 10 bulbs on a 75g+ tank comes from... Considering that the quality reflectors approach 2.75" - 3" in width, someone would be lucky to squeeze 7 bulbs over a 75g or 90g using quality reflectors. I've seen 8 T5 HO bulbs on a 120g that grew SPS well with good color. Even getting 9 - 10 bulbs with quality reflectors over a 120g would be kind of tough. T5 HO lighting is all about quality reflectors and proper bulb choices to suit your needs and taste.

Yes, 8 T5 HO bulbs will run about $200, which are a bit pricier than 2 of most any MH bulb, but if there's going to be any actinic supplementation in conjunction with the MH lighting, the cost difference is a wash by the time the cost of replacing the actinic bulbs is factored into the equation. I've seen comments referring to it being cheaper to operate T5 HO lighting than MH lighting (utility bills), but I've yet to see anything I consider to be definitive on the subject.

T5 HO lacks shimmer, but that's just not particularly important to me. Some like it, others need it to be satisified... I guess it just depends where you fall in that range.
 
On RC the comparison I got was replacing two $70 Mh bulbs every 8 months works out to ~$420 over two years. Replacing eight $25 T5 bulbs every 12 months works out wo $400. So, based on that, the cost is close enough to ne negligible, unless those dollar figures are way off. I'm looking at leaving the tank open topped with a hanging fixture so that should help with the heat issues a bit.
 
I would say T5s if you wont miss the shimmer of the MH. Cost will be cheaper montly as well as bulb replacment. And you will save some heat as well. I would switch to T5, i just dont have the money right now.
 
the tank will be a 2'x2'x4' 120gal.
 
Have you though about going with a mix, 2 HQI and 2-4 T5 HOs in the same hood? Best of both worlds I would presume.
 
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