The Reef Tank banner
1 - 6 of 6 Posts

·
Registered
Joined
·
108 Posts
Discussion Starter · #1 ·
It's getting close for a tank upgrade are there 250watt mh's that run cooler than others say with 10k bulbs. I can't seem to word my search correctly and I know the info is in this board somewhere. Any help is appreciated.

ziggy
 

·
Administrator
Joined
·
47,624 Posts
Ziggy, heat is a function of current vs resistance, thats what make filament and the gas envelope surrounding MH filament glow. Both a reg incandescent 250 watt and a 250 MH produce a lot of heat, the MH more but it produces far more lumens than the cheap incandescent.
Actually heat vs light is fairly equal.
If you have a canopy with 5 11o watt VHO tubes or the equivalent in PC lights, they are gonna to put off a lot of heat, the difference is the bigger the radiating surface to put off x amount of heat, the less intense it will seem. IE you could put your hand across the VHO tubes without serious effect, however MH bulbs scar:(
To further my example, think of a bed of coals in a bbq as opposed to a cutting torch. In both cases we are dealing with a lot of heat but in one its spread over a large area and the other is a point source, and highly concentrated.
Back to the original question, no a certain bulb is not going to run noticably different because of its K rating, allegedly E ballasts are more energy efficient and reduce consumption, but I dont see them making a radical difference in hood temps. If you run MH you need to design the canopy to pull heat away from bulbs and exchange it for cooler air. Another side benefit is that with major air movement you will increase your evaporation rate and thats good if you dose Kalkwasser to maintain calcium and Alk.
Fans and vent!!!!!!!!!!!!!!!!! is where its at
 

·
Registered
Joined
·
5,816 Posts
Well put Doug! I run two 250ww MH 10,000k german bulbs and 2 96ww PC's actinic 03 bulbs and have two fans in the hood and have the hood about 7" off the water and tank temp is 82 degrees!:)
 

·
Administrator
Joined
·
47,624 Posts
Its just really simplified basic physics, besides the Scot in me cries out for a cheap solution :D
 

·
Registered
Joined
·
108 Posts
Discussion Starter · #5 ·
Thanks doug I don't know where I thought I saw something on cooler Mh bulbs. Cheeper ; something about a true reefer never pays retail. Johnny I always enjoy your input and I assume you got the hamilton problem taken care of.

you guys are always great
ziggy
 

·
Registered
Joined
·
5,816 Posts
Yes ziggy everything is fine now! Thanks for asking!:)
 
1 - 6 of 6 Posts
Top