Recomended lighting

[Tang56]

What kind of lights would you recomend for a 8x2x2 tank in order to grom mostly all sps?
Thanks,

 

[Myteemouse]

I would suggest 4x 250w MH
OR
2x 48" 8 bulb T-5 fixtures..(or retros with individual reflectors if your a handy man with a hood over your tank.) this would be 16 T-5 bulbs..
These will be adequate...
T-5's would be less heat but more expensive to change out all the bulbs at 25-30 bucks a pop.
but I guess 4 250w MH's 20k radiums would be around 320 for 4 of them.at 80 bucks a pop.
if you must have the bluest of blue bulbs.. and said to be the best 20K bulb.

 

[kevinpo]

Hello,
I would recommend 5 400W mogul type metal halides or 5 DE HQI 250W halides with 10 T-5 HO 420nm or 450nm bulbs for dawn dusk simulation.

HTH,
Kevin

 

[Tang56]

thanks for the advice, but im undecided between the t-5's and metal halides. what is your preference?

 

[kevinpo]

what is your preference?

I prefer MH's

Kevin

 

[Tang56]

I think that's what I'm going to go with!
Thanks!

 

[Wieselsport]

are LED's an option?

 

[roscoe]

Depending on mount height and reflectors. I know with good reflectors such as lumenarcs and Lumenbrights just to name a couple you can get away with 4 250s 5 is over killl and a waste of energy and an extra bulb you have to replace IMO. I have 3 400 over my 6'x3'x2' tank because of how high I have them mounted 16'' from the water surface If my lights were lower I would use 250s. I honestly think I can get away with 2 and still have plenty of light to cover majority of the tank.

 

[Scooterman]

Depending on mount height and reflectors. I know with good reflectors such as lumenarcs and Lumenbrights just to name a couple you can get away with 4 250s 5 is over killl and a waste of energy and an extra bulb you have to replace IMO. I have 3 400 over my 6'x3'x2' tank because of how high I have them mounted 16'' from the water surface If my lights were lower I would use 250s. I honestly think I can get away with 2 and still have plenty of light to cover majority of the tank.

His tank is 8ft not 6, I'd agree 5 lights would be ideal even with luminarcs. Growing corals & keeping corals alive is two different things, If you want growth, then you want light, all depends on what you consider good growth & healthy corals. Also the kelvin chosen affects PPDF output, which is probably a better choice when determining what to go by.

 

[roscoe]

His tank is 8ft not 6, I'd agree 5 lights would be ideal even with luminarcs. Growing corals & keeping corals alive is two different things, If you want growth, then you want light, all depends on what you consider good growth & healthy corals. Also the kelvin chosen affects PPDF output, which is probably a better choice when determining what to go by.

Well I will have to 110% disagree. Definately will NOT need 5 MH lights on a 8'x2'x2'. Like I say way over kill so are you saying that I need a 4 set up for my tank 6' tank? The 3 I have under large Lumenbrights light is already spilling out of the tank. And I do know the difference between growing corals and keeping them alive. I have done both with less light. As you already know the genral rule of thumb for MH is that it has a 2 square feet coverage. So why would the 5 be neccassary on a 8' tank?

 

[Scooterman]

No he would need 4 MH If he was using Luminarcs but 5 if he was using a pendant type, so the reflector would also come into play with that. So my first line was wrong! That 2ft is only for the bigger high efficiency types not the small tight pendants like most HQI's or spider reflectors big difference, also the height off the water. What you call growth may not be the same as to someone like what Kevin would consider good growth!

 

[roscoe]

Its all good my man!

 

[kevinpo]

Depending on mount height and reflectors.

Hello,
A good point to consider! Reflector selection is as important as the bulb and ballast combination. Just like bulbs and ballasts not all are created equal neither are reflectors. Some 250W HQI bulbs produce more PAR than 400W bulbs. I tested a 250W HQI bulb the other day and got a reading of 205 PAR @ 15.5". It should typically be 500+ at that distance for high light SPS to produce good coloration. I hooked up a different ballast and the PAR jumped to 550 PAR (same bulb & ballast).

The number, placement, wattage, etc. is really dependant on what corals you plan to keep and the PAR required to produce the color you desire, keeping in mind that color is not an indication of coral health. IME about 500 PAR for 9 hours will keep most high light SPS very colorful and at maximum growth rates.

I haven't run tests with metal halides (with and without reflectors), but I have run T-5's and the difference is about 30%. I would guess it would be similar for MH's.

Regarding LEDs I would wait until the 5 watt ones are available and use 60 degree diffusers with a combination of royal blue and 10,000K on separate drivers. The price needs to come down also unless you have a large budget or a small tank

Regards,
Kevin

 

[roscoe]

Fair enough ...... You have some good points. DR Sanjay Joshi (the lighting guru himself) 500g DT is only runnig 3 400w halides under lumen max 3 reflectors and his SPS looks great. As you already know lighting isn't everything there are other factors within your system that can dictate color and growth also.