definitely yes! Maximum you should be considering is 175w x 2 and even this will be a lot of light!
Metal halides for 120g
are 2 250w mh two much light for a 120g tank?
1 - 13 of 13 Posts
you think? what if I hang them high?
you think? what if I hang them high?
Thats the perfect answer and you are able to adjust the light as you need.
Go for it.
My answer is yes and no, yes, if you would go for light hungry plants like glossostigma then it would be fine, no if you would go for most of the plants available at your LFS.
I have owned and used 2 x 250watt w/6500k Iwasaki's, 2 x175watt w/XM 10k under spider light and Lumenarcs and currently 2 x 150watt 8k Hqi '2 weeks old' over a 90 gal.
250 watters you will regret after trying them the first 3 weeks...well thats how long It took me. Be prepared for constant high water temps once on which you must cool not maybe. I did the evaporative cooling thing and that didn't work for me because it kept on messing with my water parameters so I got a chiller because it became more of a pain even though I had an auto topoff unit.
Have you ever seen what high light can do to stem plants?...I have and take my word for it you don't have to worry about wanting to buy HC, Glosso, HM etc because all your stem plants will grow sideways and compete with the true foreground plants for ground cover.
These aren't T5's where 6~10" above water will do you are talking 250watt of intense halide lighting so be prepared to be at 24+ inches to make all the above less stress on you.
I sold my 175watt x 2 /w Lumenarcs reflectors because they were to bright and I had them mounted at 20"~22" above my tank, even before I got the Lumenarcs. Going with the 150hqi is the best halide move I've made to date, they have the perfect intensity for standard depth tanks 24"~30" & 24" width, you can mount at a realistic distance above water and not worry too much about heat.
The problem is most tend to go the 175watt or 250watt route due to startup cost; cheaper ballast, cheaper reflectors & possibly cheap bulbs of ebay or others who think they are doing the right thing 'like me' by comparing with a fluorescent setup and trying to apply WPG rule to halides...big mistake! The WPG rule do not apply to halides!
I hope my experiences help with your final decision...good luck with your choice :thumbsup:
250 watters you will regret after trying them the first 3 weeks...well thats how long It took me. Be prepared for constant high water temps once on which you must cool not maybe. I did the evaporative cooling thing and that didn't work for me because it kept on messing with my water parameters so I got a chiller because it became more of a pain even though I had an auto topoff unit.
Have you ever seen what high light can do to stem plants?...I have and take my word for it you don't have to worry about wanting to buy HC, Glosso, HM etc because all your stem plants will grow sideways and compete with the true foreground plants for ground cover.
These aren't T5's where 6~10" above water will do you are talking 250watt of intense halide lighting so be prepared to be at 24+ inches to make all the above less stress on you.
I sold my 175watt x 2 /w Lumenarcs reflectors because they were to bright and I had them mounted at 20"~22" above my tank, even before I got the Lumenarcs. Going with the 150hqi is the best halide move I've made to date, they have the perfect intensity for standard depth tanks 24"~30" & 24" width, you can mount at a realistic distance above water and not worry too much about heat.
The problem is most tend to go the 175watt or 250watt route due to startup cost; cheaper ballast, cheaper reflectors & possibly cheap bulbs of ebay or others who think they are doing the right thing 'like me' by comparing with a fluorescent setup and trying to apply WPG rule to halides...big mistake! The WPG rule do not apply to halides!
I hope my experiences help with your final decision...good luck with your choice :thumbsup:
Actually the WPG rule does work with MH lights.
2x250 watts over a 90 gallon is 5.5555 wpg. Which most anyone will tell you is a LOT of light over a 90 gallon tank.
2x175 is 350 watts which is 3.888 wpg which again is a lot of light over a 90 gallon tank.
2x150 is 300 watts which is 3.333 wpg. And that is a high light 90 gallon tank.
What broke down is not the type of lighting but the WPG rule. It doesn't work so well on larger or smaller tanks. It works pretty well for tanks in the 20-75 gallon range. Not so well outside that.
2x250 watts over a 90 gallon is 5.5555 wpg. Which most anyone will tell you is a LOT of light over a 90 gallon tank.
2x175 is 350 watts which is 3.888 wpg which again is a lot of light over a 90 gallon tank.
2x150 is 300 watts which is 3.333 wpg. And that is a high light 90 gallon tank.
What broke down is not the type of lighting but the WPG rule. It doesn't work so well on larger or smaller tanks. It works pretty well for tanks in the 20-75 gallon range. Not so well outside that.
Actually the WPG rule does work with MH lights.
2x250 watts over a 90 gallon is 5.5555 wpg. Which most anyone will tell you is a LOT of light over a 90 gallon tank.
2x175 is 350 watts which is 3.888 wpg which again is a lot of light over a 90 gallon tank.
2x150 is 300 watts which is 3.333 wpg. And that is a high light 90 gallon tank.
But were that falls down is the distance the MH are suspended from the water surface - "2x250 watts over a 90 gallon is 5.5555 wpg" really means nothing because at what height are the lights? I have seen 6' tanks lit with 3 x 250 watters that had the lights up high that looked dull compared to 6' tanks lit with 3 x 150 watters that were 6" above the water surface.
Actually the WPG rule does work with MH lights.
2x250 watts over a 90 gallon is 5.5555 wpg. Which most anyone will tell you is a LOT of light over a 90 gallon tank.
2x175 is 350 watts which is 3.888 wpg which again is a lot of light over a 90 gallon tank.
2x150 is 300 watts which is 3.333 wpg. And that is a high light 90 gallon tank.
What broke down is not the type of lighting but the WPG rule. It doesn't work so well on larger or smaller tanks. It works pretty well for tanks in the 20-75 gallon range. Not so well outside that.
Agreed Rex so let me clarify. Given the same configuration of both height above water, total watts, etc the halides will be much more intense therefore the plants will responded very differenttly for each. Its my understanding that the WPG rule is based on an AH supply lighting of a given wattage 6" above water? If this is the case (I'm sure there has to be some kind of formula) we certainly cannot use the same formula for measuring a halide's performance.
well I have a 20g long with one 150w MH and it's doing really good. I have hair grass, flame moss, and wiping moss. For the 120 with 2 250 I was planning on doing HC, glosso or hair grass.
I was also asking because I have all the equipment. The tank was gonna be a reef tank but I think I'm gonna do the planted tank instead.
I was also asking because I have all the equipment. The tank was gonna be a reef tank but I think I'm gonna do the planted tank instead.
Not true at all. The WPG formula was around long before AH Supply. Watts per gallon is just that. There is no height above water in the formula. It's simply watts per gallon.Agreed Rex so let me clarify. Given the same configuration of both height above water, total watts, etc the halides will be much more intense therefore the plants will responded very differenttly for each. Its my understanding that the WPG rule is based on an AH supply lighting of a given wattage 6" above water? If this is the case (I'm sure there has to be some kind of formula) we certainly cannot use the same formula for measuring a halide's performance.
If you must know it was based on T12 bulbs with flat reflectors mounted in a canopy.
Watts per gallon is just that. There is no height above water in the formula. It's simply watts per gallon.
Pretty ambiguous formula.
Suspending metal halide lamps at different heights over an aquarium causes a huge increase or decrease in the brightness of usable light entering the aquarium. So saying a 100 gallon aquarium lit with 2 x 150 MH is 3 watts per gallon is correct, but meaningless.
1 - 13 of 13 Posts
- This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
The Planted Tank Forum
A forum community dedicated to Aquatic tank owners and enthusiasts. Come join the discussion about flora, fauna, health, housing, filters, care, classifieds, and more!
Full Forum Listing
Explore Our Forums
Recommended Communities
