MH Height

[alienz1]

Quick question, I have 2 10K 175Watt MH Pendants arriving tomorrow. I've come across various opnions on the height I need to hang them at above the surface. Right now all I'll need the light for is one carpet anenome.

Also I figure I'll start the lights at 2 hours a day and add an hour every week? That too slow? too quick?

Peace,
alienz

 

[danmhippo]

How deep is your tank from top to the sand surface? & how long is your tank?

 

[alienz1]

Oh duh,

it's your standard 55 Gallon 18" height 12" wide 48" long

 

[Anonymous]

at the depth of a 55-the 175 may be borderline for a carpet-it's not the amount of livestock, but rather the intensity of light reaching the livestock (and spectrum)at the depth of water they're in, and overall distance from the light source(read including distance above water surface.)that's the issue.

first- if you're not supplementing with actinics,and i assume you won't be, since they would block the light from the pendants-i'd suggest the lights be hung so the glass shield of the pendants is no further than 6" from the water surface.-but the closer the better-the trade off is the heat increase to your tank as you get closer to it with the lights.try 4"-and raise if necessary due to temp. increase.on a hot day, the lights can be raised higher, temporarily, with no ill effects(like a cloudy day).

don't forget to clean the glass shields at least weekly! dust and little bits of salt from evaporated splash droplets can really cut down on the light leaving the pendant!

 

[npaden]

There are people that keep their MH as close as 2 or 3 inches off the water. I personally keep my 400W MH about 6 - 7 inches off the water.

FWIW, Nathan

 

[suckair]

It depends on the angle of your reflector. You want the light to be dispersed across as much of the tank as possible. There is the issues of water spalashing ect. I would just get a good reflecctor and play with it until you get the light pattern you like. Then use that as the height model for your hood.

Randall