is there a such thing of too much lighting ? 2x 250w MH. for a 72g bow. im not sure exactly what im trying to have in my tank.
Thats a little high but what bulbs are you gonna run?
other questions you may want to ask yourself is
what hieght off water is light because of heat issues and also coral depths near top. high demanding corals near top only. canopy ot suspended light?
well, it’s almost impossible to have too much light for… clams. yeah no surprise on that one. almost everything else can be harmed though
I have had a 55gal running 2 250W MH 20K Reeflux bulbs hung about 10 inches from the top of the tank with no problems. Had SPS frags in the middle and soft corals on the bottom. I don’t see why they wouldn’t be ok. Just my :TWOCENTS
For corals and their zooxanthalae, there is a point at which they experience Photo inhibition and they cant take no more. they close up, drop algae, turn brown to shield themselves and stuff. but its rare in our tanks with man made lighting. and the big thing is not only the watts, but the distance from the corals and the depth and clarity of the water. as these increase, the light intensity decreases by the square of the distiance. so a bulb 10-12 inches off the water is really reducing the intensity at the coral . and green water will block more. and of course higher Kelvin bulbs produce less intense light. rarified to blues.
Do you already have the lights? Sure you don’t want to look at LEDs? If you add in 7 years of bulbs replacements and electrical costs the LEDs are going to be cheaper in the long run. Not just retrofit cheap knock offs, but even the very nice brand names are cheaper in the long run. Not sure if you talked to anyone about them in the LED threads or looked into them. Just wanted to make sure you were aware.
With the MH you very well could need to hook up a couple of fans or a chiller in the summer time. Depends on the size sump, turn over rate, and how hot your house gets in the summer. If you don’t have air conditioning I would NOT recommend metal halides at all.
I found it used its for a good price, sorry I don’t know the brand of bulb, forgot to ask that question. If I could find led’s for the price I could buy this light for I would snatch them up in a second. I have another question. There is no attinic T5 bulbs in this system. But he has 2 different sets of bulbs blue attinic and white. But the guy was using the white. Would my corals still have the “glow” look with mh bulbs only?
Depending on the bulb color (Kelvin temperature) 10k/14k/20k. same as cars higher the Kelvin the bluer the color. Depending on all the coral I would prob retro at least 2/4 actinics. The colored bulbs are what really make the colors pop out on the corals. Am I correct on this guys?
If you want to do a retro I have a kit I am selling. can handle up to 16’ of bulbs or 4x 48" bulbs as it was being used for.
[quote=“Cash4Cars, post:8, topic:3954”]
Would my corals still have the “glow” look with mh bulbs only?[/quote]
That would depend on the the Kelvin rating of the bulbs. A 20K MH bulb would give you a nice blue color overall with a nice pop of color from your corals. I run 14K MH bulbs and could get by without using the actinics at all if I wanted to. Just looks better with more pop when using the actinics.
you can use regular marine glow flurecent bulbs and a shop light fixture for actinics. my fixture has 2 -175 watt mh and 4 regular 40 watt flurecents. i even have a ballast you can have and maybe even the holders.
Thanks For all the Info guys !!
[quote=“Cash4Cars, post:8, topic:3954”]
If I could find led’s for the price I could buy this light for I would snatch them up in a second. [/quote]
I realize it’s likely a bit late but price and cost(IE long term cost) can be two different things. Replacing bulbs ever 10 months or every 7 years and significant electrical savings can make up the difference. I found for my tank since I already had all the bulbs, ballast, end caps, wires, reflectors, and all of that it would cost me more to jump into AquaIlluminations then it would to burn more electricity, but if I didn’t have that all already and was buying a new fixture then it would be cheaper to go LEDs. Then again I wouldn’t be paying full price for AIs either, so I suppose that plays into my calculations. Again realize this may be a bit later, but others will read and just putting it out there as info.
JustsumGuy, you are right with the different color temps, but that isn’t the full picture at all. 10K is a very general description of where a bulb peaks, but it often includes a lot more color. Many of the 10K bulbs I’ve used int he past were just plain ugly(great for growth, but ugly). The ATI bulbs that beak at 10K also peak at blue and not to much pink and yellow. Huge difference in appearance.
So Cash4Cars keep that in mind as well. You aren’t just shopping for one of those three general types of bulbs. If that was the case we’d all be using cheap bulbs found on ebay, but there PAR ratings(what help the corals) are low and their colors that reflect to our eyes are ugly.(I also don’t think they last as long either)
Happy reefing.
Thanks for that info Gorgonious. I was kind of wondering personally about the brand name bulbs vs the ebay bulbs. I know in just about every aspect of our daily living “you get what you pay for”.
I have a 45 tall tank with ten gallon sump. And I have a 400 watt mh dimable ballast set all the way down and was told by lfs that that’s alot for that tank. I knew it was it’s about 8" over the tank with a 14k plus rite bulb from e-bay. Every thing seems to thrive in the tank, when I kick on the light every thing opens up real nice. But I get alot of algae not as bad as I first did but every 3 days I gotta wipe it off or it can get crazy. I got those plus rite bulbs from 1000 bulbs.com. I of course was sketchy like everyone else when I saw the 20.00 or so price so I reserched and came across this review from Sanjay at reef central. Ebay MH bulbs - Reef Central Online Community so I gave it a try. I had it now for about 5 months and I’m about to order the 20k I think they look great. But then again what the he’ll do I know 
[quote=“Reefer, post:15, topic:3954”]
I think they look great.[/quote]
And that sir is the million dollar answer. As long as your corals are happy and you are happy they are really the only opinions that matter.
Well allmost all my corals are happy. i for the most part am happy. but i do have this bonsi tree sps, that is white with purple tips the purple kinda faded a little. and i put it the highest i could. i am thinking of finding it a home befor anything bad happens. (if i dont get a MH or LED light befor then) Thanks again for the help everyone
What specifically do you have? Is it a Garf Purple Bonsai Acropora? Do you have other Acropora or is this your first venture into SPS? SPS doesn’t translation into super photosynthetic spirit or something of the sort though some forum posters and hobby websites may make you think. It is a general term and could include some animals that hate bright light.
The color fade could mean a slew of different things. May be able to give you a little more insight if I knew specifically what it was and could see it. See if you can get a picture or video and start a new thread and PM me a link. Sometimes it could be a certain element is lacking in significant enough concentration. (I’m not sure your experience level just wanted to offer a little help)