250watt MH too much for 20L?

[gtfourmn]

Just wondering if anyone has any experience using a 250MH on a 20L or 33L?

From my research MH produces less heat then the other lights so I figure with an open top it should be sufficent.

Any inputs?

[coldwaterreefer]

mh has more heat than others i think.

[David Grigor]

Heat will be your #1 issue but it's possible. The real issue for me with MH on such a narrow tank is that you will get lots of light spill especially the higher you have to mount it to compensate for the heat issues. If you want MH on a small tank you should custom make one that is wide as it is long to better use the light.

A 20L you can fit maybe 3-4 T5s with quality reflectors. For half the total watts. Theres just no way heat generated from 250W MH will be less than 96W of T5s. Can't happen. Not for sure where you heard that but it is false. Perhaps you misinterpretting it as heat per watt ratio.

[freshfish]

I have a 110gal tank and somedays the heat from the bulb kept the tank warm enough so the heater didn't turn for a couple of days till I put a fan on the sump. Very hot.