Can light actually be too strong??

[krypton74]

I have a 35 Hex and want to convert it to a reef set up. I am looking at a MH light and it is 250W. I know i need more watts because my tank is deeper, but i certainly don't want any inverts on the top of the tank to be harmed. it is the kind of light that sits on the top of the tank. i can probably rig something up though so it sits up a few inches higher than the hood...

 

[neowind]

You never want MH lighting any closer than 6 inches from the top of the water.

 

[dreeves]

how deep is the tank? If it is 24 or less inches...the 250 should be fine.

 

[krypton74]

the tank is 22" deep. AHHH - i just am not sure what kind of lights to get. i am reading on SWF that most people run a combo of VHO along with the MH for a color balance. The top of my tank is so small i am not sure how i would accomplish that - not to mention MH lights sticking out all over the place look kind of silly. if there needs to be 6" of space between water and bulb - for sure i need to elevate the MHs. i guess rigging something is the best bet..:notsure:

 

[mep]

double ended 250 hqi low profile
my fixture is 3.5 inchs tall with uv glass shield built into fixture

 

[robchuck]

Originally posted by krypton74
...i am reading on SWF that most people run a combo of VHO along with the MH for a color balance. The top of my tank is so small i am not sure how i would accomplish that...
This is an easy problem to get around. You would just need to choose a bulb that is bluer in it's color temperature, so that you don't need to run actinics for color balance. A good bulb to choose would be anything higher than 13,000K kelvin. A few recommendations for you to look into are (not necessarily in this order): PFO 13,000K, Hamilton 14,000K, Coralvue 15,000K, and at 20,000K XM and Radium are good bulbs.
I also second what MEP said about the 250W DE HQI idea. The pendants they mount in are compact and easy to mount over smaller surface areas. There a quite a few double ended bulbs on the market that are rated higher than 13,000K.

 

[brooklyn johnny]

krypton everyone here has the right idea. Here is my 54 corner that is run with an unsupplemented 250 watt 20k AB bulb. There is a thread on it here if you're interested...
Hope that helps...

 

[krypton74]

thanks everyone for the replies. this will give me some great starting places. I will post my final decision soon! yikes - to the drawing board my friends....
i also need to add that your tank looks awesome and the hanging MH fixture doesn't look a bit silly. it looks normal and great! Thanks for the lic and the link...

 

[dreeves]

They have 14k and also 20k which would eliminate the need for actinic supplementation as well.

 

[pacopetty]

Krypton74 welcome to the fountain of knowledge! These guys are great and back it up by having some of the nicest tanks you will ever see.

 

[h2oengr]

Nice corner tank Brooklyn!

I'm not a fan of the hanging lights and the 6-month lifespan of the MHs. I've got PCs on my corner tank.

 

[dreeves]

Brooklyn used to have a pretty slick little kitchen nano...he takes ghetto to an entirely different meaning...

 

[brooklyn johnny]

Thanks... I think...:notsure:

 

[lafish]

I have a 30 gallon hex...and was facing the same problems w/ light and space at the top of the tank. I got a pendant from PFO that has a combo of halide (choose a 175 or 250 watter, 10K looks good on my tank)...and it also has 2 x 28 watt PCS (I use the "03"s). Everything looks so good. The cool things about this pendant/hood is that it is only 16 inches across...and will prob fit nicely over your tank w/ the MH bulb 8 inches off the top of your tank. Price is not cheap though...you mix and match a MH bulb w/ a ballast, get the pendant (which has a built in ballast for the PCs and a fan, reflector)...I even added a moonlite....

 

[krypton74]

I called www.hellolights.com and they were super helpful and took about 15 minutes to give me advice even when i wasn't ready to purchase yet. What we settled on is my husband is going to build me a custom canopy for the tank. we are getting some jumpy gobies, so topless isn't an option (on the tank that is ). Then we will inset the lights into the top and go from there. MEP - we are going with the double ended something or other... I can't remember just now, but Brian at hello says all critters seem to respond well to that light spectrum. So thanks for that advice. Will post a picture of canopy after its built....

 

[beerformep]

i got the 20000k xms 2 175watts and they are perfect.I like the blue look they give compared to a 10000k which was too yellow imo

 

[technik]

Originally posted by H2OENGR
I'm not a fan of the hanging lights and the 6-month lifespan of the MHs. I've got PCs on my corner tank.
MH's last 12-14 months. My PCs loose spectrum at 6-8 months.

 

[brooklyn johnny]

Sanjay Joshi spoke locally at one of our meetings and mentioned how he gets around two years out of his 6500 Iwasakis, whereas most people running 20k radiums change them out at around six or seven months, so it really depends when it comes to metal halides. I hope to get close to a year on my DE 20k AB bulb, but that's to be seen as I got the bulb in January when it first came out... My 10k DE ushios I plan to get a year out of... we'll see...

 

[brooklyn johnny]

Hey Kip are the DE radiums out yet, and if you've seen them what do you think?
I am not a radium guy on my sps tank, but many local guys run them (Robz, va_reefman), and still get only around a half year out of them even run on electronic ballasts not overdriving them. Like everything though it depends...
I too agree that anything acclimated enough could take a beating from light...

 

[brooklyn johnny]

I'm sure Radium would be happy to hear you say that... sort of like Jello instead of gelatin and Band-aid instead of bandage nowadays...
The last I heard was that they've been having problems for a while... I went with the DE 20k AB bulb and am happy with it on my corner tank. I spoke with my bulb vendor and many people had problems with the 20k double ended XM bulb firing, and on top of that many people called it too purple.
My 250 watt DE 10k bulbs are great and compare with SE 400 watters, but my personal opinion of the 250 watt 20k DE is that it doesn't compare to the 400 watt SE 20ks... I haven't been following many bulb threads... anyway, I'm kind of off subject and rambling...