metal halide

Im thinking of doing a metal halide diy project on a 75 gallon im going to be using 2 mogul socket kind of light i was wondering about how many watts i should use in that big of a tank i only have mushrooms keny tree and ricorida in there now

 

175 watt 15K Iwasaki is a fantastic bulb. A little more expensive but you will get the output of the best 250 watt 10K without the heat and electrical cost. Be sure to use this bulb with a electronic ballast for best output.
175 Watt 15000K Metal Halide Bulb - Iwasaki, Mogul Base

 

so just a 175 watt will be enough

 

Not necessarily, But that particular 175 watt is enough for any corals you may choose including SPS. That bulb is crisp white with the slightest hint of blue. It is a great bulb and nearly 50% brighter than any other 175 watt bulb.

 

I would be skeptical of what you are saying. I'm not saying you are wrong, but I would like to see some PAR readings from that bulb before comparing it to a 250w bulb.

As for a 75. If all you ever want is soft corals and possible lps, I would use two 175w bulbs with appropriate ballasts. If you may want sps, I would use 2 250w bulbs and ballasts.

 

A pair of 175 would work for SPS (except the very most light demanding) if kept in the upper reaches of the tank. Softies, leathers, and LPS can be put anywhere and be very happy.

 

I have a 90 gallon which is I think 4" taller with Dual 175s
I had 10k coralvue bulbs and they looked great but needed a hint more blue for my taste and were getting a little old anyway.
So, I just bought a set of Coralvue 14k and they look AMAZING. I found a great deal on them to, 38.00 each
I run them on Cool Touch Lighting magnetic ballasts.
I have all soft corals and they have always done fine. I run the bulbs about 6" off the water with no glass. I also have a polished reflector in the canopy.

 

would the metal halide be better for the corals than what i have now is 54x4 2 10k and 2 actinic blubs

 

I don't think there any "better for the coral" I think they look better though.

 

Have you ever seen a tank with them on it? It looks spectacular the way the water shimmers