How many LUMENS for a 75g reef tank?


Premium Member
This whole lighting thing is turning out to be more confusing than anything else. I'd like to start adding some corals to my tank, but I want to get the lighting right first. Don't confuse me with MH/PC/VHO, and all that stuff... I just want to know how many lumens (not watts) I need for a 75g reef tank.


Premium Member
My budget is unlimited, I just want to make sure I have enough lumens for coral. On the other hand, I don't want to have to buy a chiller because of the heat from the MH.

I'm probable going to customer make a canopy. There has to be a rule of thumb on lumens. If I can get enough lumens with VHO lights, I'll go that way. I just want to know how many lumens I need.

By the way, watt for watt, MH puts out more lumens than VHO and PC, and they put out more lumens than standard flourescent. Correct me if I'm wrong, but the corals couldn't care less about how many watts I'm running through the fixtures, they just want the brightness (lumens), right?

They also want the proper spectrum, too, but I can do that with HO or VHO lights.


Seasoned reefer
<a href=showthread.php?s=&postid=9891316#post9891316 target=_blank>Originally posted</a> by demonsp
But my t-5 dont seem to support some LPS.

I guess too much light.


Team RC
I think you might have watts, lumens, and PAR confused a bit. Corals really care about PAR. Halides on a good reflector are going to put out the best PAR closely followed or even equal to are T5, then VHO, then PC etc.. All depends on how many lamps you run and the wattage of course. Here's what I would do.... I would come up with a list of the corals you want to keep first, then we can help you with your lighting needs. Softies don't require near the light of SPS and so on. Start there and let us know. :)