Height of light from surface?

[Cory]

How high should my 250 watt radium metal halides be from my tanks surface? Tank is 20" tall. 125 gallons. Ive got the Hamilton Cebun with 3x 400 watt radiums and 4 80w t5s. I drive the radiums on the 300w setting electronic balast because my circuit cant handle 400w x 3.

 

[Bpb]

12-15” or so ought to spread fine

 

[Cory]

12-15” or so ought to spread fine

I have them lower, about 9" off the water surface. Corals are growing good. Should i raise it?

 

[legionofdoon]

I've had my halides from 10 to 18. Are you running 250 bulbs at 300 or 400 bulbs at 300? DE or Mogul? I used to run 175 10k mogul ushios at 10, 400s at about 12 and DE 14k 250 Radions at 18. The ushios both wattage were on a 75 the 250 Radion was on a 40B. If your corals are growing well and heat isn't an issue then just leave it alone. That being said 10k ushios were probably the best lights I've ever used you don't get the LED pop but it definitely looks more natural and corals love them.

 

[Cory]

I've had my halides from 10 to 18. Are you running 250 bulbs at 300 or 400 bulbs at 300? DE or Mogul? I used to run 175 10k mogul ushios at 10, 400s at about 12 and DE 14k 250 Radions at 18. The ushios both wattage were on a 75 the 250 Radion was on a 40B. If your corals are growing well and heat isn't an issue then just leave it alone. That being said 10k ushios were probably the best lights I've ever used you don't get the LED pop but it definitely looks more natural and corals love them.

Im running 400w SE Raduims at the 300w setting. One thing I noticed is im not getting glitter lines too much, maybe they are too low?

 

[outhouse]

I ran my 175W 11" above the water in a 30" deep tank and had amazing growth

Its the heat being so low that is your real issue

 

[Cory]

I ran my 175W 11" above the water in a 30" deep tank and had amazing growth

Its the heat being so low that is your real issue

I live in Canada so im not concerned about the heat, just in the summer it can be a problem.

 

[outhouse]

I live in Canada so im not concerned about the heat, just in the summer it can be a problem.

Your good provided your not putting sensitive corals up top

 

[Dodge Ram]

So moving to 250 watts in a 20 inch tank you would need to be about 12 inches above the water surface.

 

[Cory]

So moving to 250 watts in a 20 inch tank you would need to be about 12 inches above the water surface.

I guess thats if you dont have a glass top? Ive got a glass lid so a little less is better then?

 

[legionofdoon]

How high should my 250 watt radium metal halides be from my tanks surface? Tank is 20" tall. 125 gallons. Ive got the Hamilton Cebun with 3x 400 watt radiums and 4 80w t5s. I drive the radiums on the 300w setting electronic balast because my circuit cant handle 400w x 3.

Ok

Im running 400w SE Raduims at the 300w setting. One thing I noticed is im not getting glitter lines too much, maybe they are too low?

Probably but if you are used to LED the glitter lines are more subtle. It's one single point rather than multiple single points.