lighting

i know the watts per gallon is out of date so i had to ask would a 150 w metal halide pendant work on a 20 gallon long tank im looking to keep all kinds of corals

 

Yes, that would be plenty!

 

i was kinda worried about the length of the tank wich is 30 inches would a pendant reach that far across?

 

With a tank that long and that shallow, you'd be better off with a 30-inch, 6-bulb T5 unit. It'll give you far better coverage with a lot less heat.

 

+1 to Mr.Bill although 2 or 4 will do just as well. The MH will not cover the whole tank. I suggest a DIY canopy with the T5HO to get coverage across the whole length of the tank.

 

but it would be the right wattage if the tank werent so long

 

Yes it would be fine.

 

If you prefer MHs, with a 20g you could keep just about anything with a 70MH and it wouldn't have the heat issues. It depends on the reflector and height, but at a typical height, with a typical reflector, you'd probably have some slightly darker areas for about 3" on each side. T-5s would provide better coverage and also would not have the heat issues.

 

how would a 70 watt doo on a 10 gallon