metal halide lighting question?

[J_Geisinger000]

I was thinking of switching from 175watt metal halides to
400 watt

my question is how much more heat will the 400's put off I dont have a chiller just fans in the canopy

 

[sir_dudeguy]

if you've got good fans, it shouldnt be bad. How many and what sized fans do you have?

 

[J_Geisinger000]

right now just 1 4" fan but I can add more on the other end

 

[J_Geisinger000]

^^

 

[sir_dudeguy]

i'd say try it how it is...if you have to, you can always add that extra fan

 

[J_Geisinger000]

Im just worried cause my tank runs at79 - 80 degrees now
with the 175's

 

[sir_dudeguy]

oh i c....

 

[J_Geisinger000]

anyone else got anything to say

looking for all the opinions I can get

 

[The_Alchemist]

just a question..

why were you looking into getting the more powerful halides?

 

[J_Geisinger000]

<a href=showthread.php?s=&postid=8074761#post8074761 target=_blank>Originally posted</a> by The_Alchemist
just a question..

why were you looking into getting the more powerful halides?

I am going with mostly sps and I dont feel that the 175's are strong enough for good growth and color

I could be wrong though maybe I should give them a chance for a while and see how well the growth process goes

 

[IndyReefMan]

Do you have a sump? If so, you can always position a nice, big fan blowing across the top of it.

 

[drives300]

I think it may be too much heat, before you switch are you using 10k bulbs, I might try that it will give you more white light and since you have actinics color should look good

 

[sir_dudeguy]

what would that do tho?

 

[gman19]

400W is over twice the heat dissipation you currently need with the 175W bulbs. How deep is your tank?? Are 400W really necessary?

If you're enclosed within a canopy I'd definitely suggest adding more fans.

I run 3 175W pendants over my tank and the top is completely open. With a chiller I keep it at 77 degrees and the chiller does its fair share of running at a room temp of ~73-77F. I lose about 10 gallons of water a week during winter months and about a gallon a day in the summer months. No additional fans running across the waters' surface, although I am considering adding some.

 

[cw150]

Why not go with 250s? 400 w for a 90 g tank seems like overkill to me as most tanks that size aren't so deep that they need it.

 

[sir_dudeguy]

250's would be multiple 250's right? wel...250 and 250 makes 500...thats more than 400.

 

[dcombs44]

<a href=showthread.php?s=&postid=8078655#post8078655 target=_blank>Originally posted</a> by sir_dudeguy
250's would be multiple 250's right? wel...250 and 250 makes 500...thats more than 400.

Yes, but the 400w will be more intense than the 250s as far as depth goes. Someone will have to back me on this because I can't remember exact details, but for up to 20" of depth, use 175w, up to so much more use 250", etc. You should also have a bulb every 2 feet of tank, and not use a bulb for more than 3 feet of tank. EX. You could use a single bulb on a 3 ft tank, but need 2 for a 4 ft tank....I'm sure there's an article that could explain that a bit more clearly, but I really don't think a single 175w is going to get you where you want to be on a 90 gallon.

 

[sir_dudeguy]

oh i see. I thought you were saying something like 400 watts would be stronger than 250...but the higher wattage just gives more punch into the water, right? and with that higher punch, you get higher heat going in the water too? I think i'm with you now

what would 150 and/or 70w be good for? (depth wise) and at that depth...is it the same intensity as it is at the top? i'm not real good w/mh's...just a pc guy myself for now.

I've read that for metal halides, they're good for a 2 by 2 by 2 square...is that true? i'm guessing the higher wattage ones like 400 would be a bigger square?

 

[dcombs44]

As far as the square, I pretty sure it's all the same, and the depth is the only difference. And no, they are not as strong at all depths. That's why you need more wattage for deeper tanks, therefore I don't think a 175 will do what a pair of 250's or 400's would do on a 90 gallon. I'm running dual 250's on my 55 gallon. It's 4 feet long, so I need two bulbs, and it's 20 inches deep so I went ahead and used 250's. My canopy is about 12 inches off the water and it has a vented top and open back. If needed I could also run a fan over the sump or display tank to disipate heat. Again, I'm not sure the exact specs on depth for each wattage, but I would say at least 250s for the 90 gallon. I'll see if I can find the recommended wattage for 24" depth (normal 90 gallon depth)

 

[dcombs44]

This info is from www.premiumaquatics.com


Metal Halide: This is your most powerful form of lighting. A halide bulb creates an arc of light so bright that it can spread up to a 36" wide tank. It's the closest form of lighting compared to the sun. You can use halide for soft corals, lps, sps and clams. The most common use is for those wanting more sps and clams. Some guidelines are 1 halide bulb for every 2 feet of tank, up to 3 feet. 175watt up to 24" deep, 250watt up to 36" deep, 400watt for deeper tanks. It's very common for hard core reefers to use 400watt on even a small 30 gallon tank. When it comes to sps and clams, they can handle and thrive under intense lighting. With halide, you also need to consider the Kelvin, which is the color temp. 5500K warm white, 6500K warm white, 10K Crisp white to blue tint, 12K-20K blue tint. For mixed reefs, we recommend the 10K bulbs, for sps and clams, we recommend the 65K's. If you go 55-65K, we highly recommend VHO or PC actinics, they will improve the overall color and look of the tank.