2x150W vs. 1x250W

[Jsilva1880]

I have a 46g bowfront. The tank measures 21" deep. Any opinions on using 2 150W HQI vs 1 250W HQI? I am new to this stuff and trying to decide which way to go.

 

[maxfischer]

do you have a center brace?

 

[Jsilva1880]

I do have a center brace. I have already thought about the shadow. I have heard of people replacing the center brace with a clear acrylic center brace though.

 

[dedfish]

My 36bow has the center brace replaced with lexan from HD. The guy I bought the tank from did it. He drained a bit of the tank, braced it with a clamp, and then cut the center brace out leaving about 2 inches on each side. He glued it with gorilla glue and used 2 nylon bolts on each end.

 

[Jsilva1880]

Yea I have heard of alot of people doing it that way

 

[NateHanson]

Depends on the sort of fixture you're going to use. 30" can be a lot for one bulb to illuminate. The ends of your tank might be a bit darker than the center. I'd say a standard spider reflector can light about 24" real well. Some of the newer reflectors can certainly do better than that, but I don't know if you'd want something that size over a 46g tank. For low-profile, the 2x150 would probably be better.

 

[Jsilva1880]

Its actually 36" if the 30" you are refering to is length.

 

[Arthur1]

Yes its a tough call 2, 150 watters will get a better light spread but if you do the mod a 250 with the right reflector would be better IMO. You'll get a get spread and more depth penetration. As the old rule of thumb went it was one halide per 2' squared. You didn't say if you were going to have supplemental lighting either! Have fun.

 

[Jsilva1880]

Well I was thinking about adding supplemental lighting if I decided to go with the one 250. A couple of T5's maybe??

 

[NateHanson]

Its actually 36" if the 30" you are refering to is length.

No question then. Definitely do 2x150. A single MH over a 36"x12" tank will have very uneven light. Even with supplemental light you'll have a much brighter center and dim ends. I had a 30g with a 175 and 2x36" VHO, and the light gradient was very noticeable.

 

[Jsilva1880]

ok, i got one vote for each. anybody else have an opinion?

 

[iandawson]

I currently have the 46g with one 250W MH and supplementals. I like the greater penetration of the 250, but the edges are a little dimmer (only noticeable without T5's) I use this setup to grow sps in the center top and my sps around the sides and bottom with the clams.

 

[bigdog]

put aluminum foil on center brass

 

[bigchippa]

I have ben in your position before having always had corner bow tanks. I have tried both fixtures on my 54 and my 92 and I found the 1 250 better for me I like sps aswell as lps ect. Depends on what corals you are targeting, softies lps and zoos go with 2 150s if you like primarily sps go 250. If you go 250 in that tank you will have few places for lower light corals.

 

[maurod]

Go for T5's

 

[Jsilva1880]

what is putting aluminum foil on the center brace going to do?

 

[JayM]

The aluminum foil comment was a joke

 

[mikede]

What are people doing about the center brace? say it was an AGA 90gal, 48Lx18Wx24T, and you wanted a reef with MH? Is the heat so much at 8 to 10 inches suspended above it that it will melt the plastic center brace?