how high to mount MH in canopy???

[tim000]

I have a 175w MH, and I am getting ready to mount it to the top of my canopy. now with the bracket screwed in the bulb will sit 2.5 inches from the surface of the water is this ok (safe)???
thanks

 

[Lunchbucket]

umm, i would say no. most say at least 6" off the water. if you get one little splash you will have a broken bulb in your tank

others that have actually don't MH can help but i have heard 6" min.

later
Lunchbucket

 

[tim000]

thanks , has anybody mounted one this low before and had success with it?

 

[Bradbendr]

Tim, I have 3 400 watters 10 inches above the water, and they still get a little splash on them from time to time. I would be very leery about mounting something that hot so close to the surface. Very apt to break, and the heat transfer to the water would necessitate a large chiller.

Good luck !!

 

[DJ88]

I have my 250 mounted about 6 inches above the water.. never had a bulb break.. And it does get some splashing. I clean it from time to time to get rid of the salt build up.

 

[AuroraDave]

7". I have 250s in a 14" canopy. With the fixture & airgap they are 4+" from the top. And with the tank trim that the canopy rests on, you lose another 2.5"

 

[neurotech]

I am awaiting my 250w delivered soon, but am confused. To All: When you mention the inches from the tank, do you mean from the bulb or from the pendant/fixture? To the tank or to the water surface?

 

[fishfarmer]

I have my 175 watt MH mounted horizontally in my hood. I have a glass cover between the bulb and water surface. Water surface to glass is about 2", glass to bulb is about 1". I have a 4" fan blowing in the hood from one side and vents near the MH bulb. The glass gets warm to the touch. I don't have any heat problems in my tank.

 

[DJ88]

Bulb to waters surface for me..

 

[tim000]

I will try to shim my canopy up another 3" which will give the bulb to the water surface a 6" gap, and maybe I will mount a little peice of glass in between the bulb and water. I hope this works

 

[wastedincome420]

From what I have read on many BB's is that, you want to mount the MH's atleast 6" away from th water inorder to have the proper lighting area.
If you have the bulb too close to the water A:the bulb may break B:it won't light the same amount space

 

[HARRISON]

and c. it will heat up your tank...