250 vs. 400 MH on a 75gal. 20 in. deep

Hello everyone

Its nice to be here ive read most of the forums and they're great,
Well since i'm about to drop the dime I was wondering everyones opinion on the MH's know its drawn out subject but hey its alot of money sooo what I'm wondering is will the 400 fry fish. A chillers not a problem but I dont want
to really overkill it. I was also wondering which manfactuer everyone thinks
has the deal on like 2 pendants and a dual ballast and does anyone use uv resistant glass under their MH?

Thanks
Ricky

 

I favor HQI lamps in a Hood They come with filters and all necessary fans and other parts

 

$.02

I have dual 175's over my 75gal. and I def think its not nearly enough, especially if you go 10K or higher. Crazy thing is 4x40watt standard fluorescents were great!? So I think I would go with 400's. If you think its too much then put a piece of screen? under it too intercept some of the lumens or lux or photons or whatever.

 

Hi darkliteseeker,
I have 2x400 watt MH with 2 x 110 watt VHO Actinic's.
I have SPS, LPS and leather corals along with fish in a 75 gallon tank.
Everything seems to be happy, In fact 2 of my rose Bubble tip anemones are attached to the to the glass at the top of the tank, Just kicking back and getting a tan.8) ;D Also I can put my SPS at the bottom of the tank and they still do just fine.
The only problem I have is in the summer I have to either run air conditioning or my chiller, + The electric bill gets a good kick start with 1020 watts of lighting running for 8 to 10 hours a day : ........... John

 

just wanted to say thanks for the replys ;D

 

IMO - the 250W MH's will be plenty for just about anything that you want to put under them. The 400W bulbs will also work fine, I'm just not sure if they are truly needed? There are plenty of selections on a pendant light. You can do a search and compare them.
You do not need UV resistant glass under your mh unless it is a HQI bulb. I believe most HQI assembly's come with the glass as standard on a pendant.
Welcome to 3Reef. I'm sure you will enjoy reading the posts and learning with the rest of us.
Jim

 

uv resistant glass?

Sorry if this needs to be a seperate post, but the answer should be a one time thing. What is the purpose of uv resistant glass for an aquarium? Regular glass only transmits a small portion of available uv radiation anyway (~10%). Normally uv resistant glass is used only to protect delicate objects like paintings from damage by that 10% of uv rays. Homeowners can get low-e glass to protect their furniture in the same way. I don't imagine saltwater animals are susceptible to uv damage though, because water also attenuates uv rather quickly?

 

Normal Metal halide bulbs (normal meaning, mogul base single ended) Come with a coating on them that filters out some uv light. This is done this way on purpose. A double ended bulb does not have this protection or coating (however you want to look at it) That is why the manufacturer who builds the complete fixture will supply this glass or the light bulb manufacturer will tell you that it is required.
I am not saying for a marine environmet that it is a requirement. Just implying that the manufacturer suggests that it is in an industrial environment.

Jim

ps: I read somewhere on the advanced aquariust sight (I think) about the pros and cons of using the filter with an hqi bulb. I cannot remember right now off the top of my head