Need help on lighting.

[Prince916]

I have a 100g 6' long tank. I need help on which lighting to use. I currently have a fixture with 6-65watt pc. But i also have a retro 2-175watt mh. Which light would be best for me to use and what can I grow? BTW i am only planning using wether a 6-65watt pc or 2-175watt mh.

 

[aquarius77]

I would say the metal halide, 3x 175 would better cover your 6 foot tank though.

 

[Prince916]

But if i used the mh what can i grow with it?

 

[mrgreenthumb]

I would say it depends on what corals you want to keep, if you do wantg to be limited in the corals you keep go mh, and at least 3 for that long of tank, and if you are going to use mh you might as well use at least 250's and use your pc for actinic supplementation for best results. If you are more into the softy/lps side of things then i would just use your pc's and 2 175w mh's. Thats just my 2 cents. T

 

[duece bigilo]

if it is a regular 72'x18x18 tank and using 3x 175mh anything you want including clams and sps.with sand thats a very shallow tank and you wont need the light to pentrate very deep in the tank

 

[AugustWest]

i have a 110 (6'x18"x20") and originally had 4x96W CF w/ a 175 MH in the center. when one of my CF ballasts blew i almost went 3x175MH w/ 2x96 CF actinics. instead i'm running 3x80W T5's on and ice cap 660 and the 2x96W CF. i am patiently waiting another CF failure to add the last 2 80W T5's (i cant quite fit 6 in my canopy). I keep mostly softies but the handful hard corals i have are doing well.
hth

 

[Poseidon]

You could do the 2x175's, and then have Acans and other low light corals out on the edges. I have to have my acans in the shade of a huge cap or else they melt under my lights.

 

[Prince916]

Opps i made a mistake. WHen i said 6' long tank i ment 60" long tank. Sorry for not reading through my post. But i guess 2-175watt mh will have to do. For now i am only trying to keep soft and lps. Then when i get my other job then i will start keeping sps. But will soft and lps coral grow faster if i use the mh or the pc or will it be the same?

 

[cparka23]

For 60" it shouldn't be a problem to go with 2x175W MH as long as there are no braces obstructing your lights. You should be able to keep sps when you're ready to expand beyond lps and softies.

As for growth rates between two different lights, that's difficult to say. Light is only a small factor, albeit an important one. What I mean is this: your lighting may be perfect, but a coral could grow slowly for many other reasons. That being said, starting with MH would be better if you plan to move into SPS in the future. I think it's better to plan out the equipment correctly the first time rather than to constantly upgrade.

 

[MarineManiac]

surprised no one has mentioned this yet, but bulb choice will play a critical role in what organisms you would like to keep. 10k's will put out a nice white/yellow look and more use able light than say a 20k deep ocean blue look. more light demanding corals (sps/clams) will like the 10k and a majority will do fine. acans/zoas will POP under a 20k though. you need to figure out what you want to keep, and how your tank is going to be arranged before you buy some nice quality bulbs. (ushio, XM ect.)

 

[reef-nut]

If you are doing SPS or LPS you will need the halide, but if you are doing softies only you only need PC's. You can do PC's and still do some LPS and be fine. Ask all these halide lovers where there zoa's are at, they are hiding them under rocks from there halides.

 

[aquarius77]

A 5 foot tank with 2x 175 of a higer kelvin will not be overkill for z's n p's IMO if you see the corals growing away from the lighting you can raise it up some. With quality reflectors im sure you could keep a wide array of corals in that tank with the halides. Reef nut is correct though, i have 2x 175 on a 30 breeder and my zoos need shade. Tank is 36x18x12. Tanks look sooooo much cooler under halides vs pc imo and ive done both personally and prefer the halides shimmer lines and overall look.

 

[Prince916]

I guess i'll just use the pc's for now and when im ready for sps i'll just use the metal halides.

 

[cdbias2]

This is why people mix 10k or 14k HQI's with actinic VHO's or T5's.
Best of both worlds.
You're also able to get a sunrise and sunset effect with timers.