The thinking behind how many light fixtures...

[Pola0502ds]

Can someone explain to me the thinking behind how many light fixtures you should put on a tank? Specifically LED and you also welcome to talk about MH and T5’s as well so this become a useful thread. I have a 48” x 24” x 24” tank and I’m going to make the jump from T5’s to LED. The only information I have is by what the manufacturer states on their website what the coverage is such as 24x24, 24x36, 24x48, etc.. That is great but when you come to a forum like this and look at other tanks you see more lights than what is recommended. If I wanted to go with Radions, the coverage is 24x24 and on my 48x24 tank that would mean I need 2. However, I have seen the same tank with 3 fixtures and even 4 sometimes. What is the thinking behind that? I know what you are trying to achieve and what type of reef you have such as LPS, SPS, Mixed, goes into play but the manufacturer never says anything about how many lights you should have based on reef type. 2 radions on a 48x24 should get the job done successfully whether or not its LPS or SPS. So what is the thinking behind how many light fixtures to put on your tank? It would be so nice if there was some sort of a chart that listed model, reef type, etc, and told you how many to purchase.


What I am after is, I don’t know which direction I am heading yet with this tank. Right now I have the cash flow to purchase whatever brand and QTY so 6 months down the road I want my lights to be the best for either mixed, LPS, or SPS. Right now I’m looking at the AI HYDRA 26 and kessil ap700. I talked to AI and the salesman said he recommends 2 of the hydra 26 models and not the 52’s. However, I have seen members here with the same size tank with 2 of the 52’s. Is that just wasting money or is it providing something considering you can spend half the money and have 2 hydra 26’s.


Side note, anyone have the vervve yet? I am also considering this.

 

[saltyfilmfolks]

Food for thought from earlier today. Par requirements and desires aside. And coverage considered.
https://www.reef2reef.com/threads/clear-water.244562/page-2#post-2875204

And paste

A Lighting guy's .02
A kessel is about 3in or so source and shoots a beam into the tank. A MH is 4 to 12 or more and washes a tank in light. A t5 is a broad SOURCE over the entire tank.
Low budget movies always look crummy as they shoot a light at the actors, and its called "Sourcey". It can be used to good effect BUT. Ususally is too contrasty and doesnt dig into the nooks and crannys.
In big budget movies there are LOTS of lights and generally the technique is to use large sources12'x12, 20'x20' on a stage to emulate natural outside light(outside has a huge SOURCE< the sky) see jungle book shot in LA.

This is one reason I like Canopys on tanks. I line mine with reflective material, tinfoil and pro photo stuff, or soft mylar. The reflected light is captured and sent back from all angles and put back into the tank creating a much larger source. I have done this on all my tanks, MH LED and T5. There is a noticeable difference.
if you want to do a cheap mock up get insulation board and cut it and tape it to the tank.
The other reason I use canopy's, I look at lights all day and dont want to at home, and I paid bank for that light I want it ALL in the tank.

 

[Kershaw]

+1 on the canopy with reflectors. I plan to build a floating canopy for my system. Not as good as full canopy. But will help. Honestly any led fixture out there will do a 24x24 area. The kessil ap700 will allegedly do a 48 x24 area. I have kessil a360, on a 48x30 tank. They look great but I cannot grow sps near the edges. They always grow towered the light. might want to look at the features that you want and look at tanks running the lights you are looking at. I would love to get a ap700 but I am a kessil fan.

 

[Pola0502ds]

Thanks for the insight. Im assuming you only have 2 lights on your tank?

 

[Kershaw]

Yes I do. 2 kessil a360we. I think every now and then adding t5 lights with them. But don't want to Chang bulbs mainly because I had a large colony shadowing itself.