150W Metal halide for tank?

[Electric45]

for what reasons? Too much light and not enough nutrients??

 

[jcardona1]

for what reasons? Too much light and not enough nutrients??

Yes. Freshwater tanks work very differently than saltwater. You cannot add high light and then not add co2/ferts. The three have to be in balance. And in freshwater, 2 T5HO bulbs over almost any tank will be considered medium to high light. So with metal halides, you'll be well over high light. Without adding high amounts of pressurized co2 and ferts, the tank will end in disaster.

This is my tank. It has two T5HO bulbs about 8" over the tank. I add a ton of co2 and ferts...and I STILL battle algae. Imagine what'd you get with MH and no co2/ferts?

 

[jcardona1]

Here's a chart that shows where MHs place on the lighting scale against T5HO and others. As you can see, even at 3ft above the substrate you're still at high light. Trying 'high light' without co2/ferts is a bad, bad idea.

 

[jcardona1]

So here's a question, why MH? Because you already have the fixture? Why not sell it, and use some PC or T8/T12 fixtures? That would work a lot better if you're going the low-tech route, where you'd want to be in low to medium lighting.