Thinking of switching from T5's to MH's. Need Advice

[tthayer]

Hi All,

I am thinking of switching from T5's to Metal Halide's and was wondering what wattage and how many lights I should be looking at.

The lights will be placed on a 90 Gallon tank with dimensions of
48L x 18W x 24D.

I was thinking 2 250W but then after reading posts, started thinking that I should maybe be looking at 400W.

Any advice would be appreciated.

Thanks.

[badonkadonk]

Generally for 24" depth 250W bulbs allow sufficient light penetration to the bottom to allow plenty of options for types of corals at/near the bottom. I think 400W is overkill, but then my electric rates are high. Just get a good reflector, Lumenarc/bright, and you should get good coverage with 2X250. Also might want to leave room if you can for a T5 or two in case you want to run lower K bulbs for the halides (12K Reeflux e.g., or even 10K XM). That will give you more options than if running halides only; it will provide more par for growth while still allowing for a nice blue from T5 actinic+. Though the Phoenix 14k DE is a nice bulb for which you get good PAR and a decent fluorescence w/out added actinics. Just that there are fewer options overall when going DE vs. SE.