I think thats just a matter of visual preference. However, if everything is growing well, why change it? (If its not broken, dont fix it) Are you just trying to save money or was there a reason you were thinking of this?
I agree with Kathy, why only 4 hours? IMO MHs should be on at least 6 hours. I run my 250s on my 75g for about 7 hours with the actinics supplementing them. The only reason I have the actinics on is because I have some crappy MH bulbs that I cant wait to get the money to replace lol
Even though I'm new to the whole reef scene, I feel that I might be able to help out in this situation. I actually work for Con Ed and my primary job function is looking into high electric/gas bills.
How many watts are your actinics? If your MH is on for a total of 4 hours per day @ 150w, it's a total if 18k watts per every 30 days. That would add up to 18kwhrs per month or approximately $5.00 per month (give or take).
MikeyZO.......you're looking at 2 kwhrs per day or 60 kwhrs per month. Somewhere in the neighborhood of $13.00-$15.00 per month or .43-.50 cents per day for your 2 MH's alone.
hijinks..........if your actinic 96w bulbs X 2 for 8 hours per day you're looking at 46.08 kwhrs per month or roughly $10.00-$12.00 per month. 1/2 of that if you're going to reduce it to 4 hours per day.
Of course these are rough estimates.
The formula is pretty easy. Watts X hours used per day / 1000 equals your Kwhr usage per day. Figure the average month is 30 days multiplied by the price per kwhr (including delivery costs) and you get a neighborhood dollar amount per month. The same formula can be applied to your household lighting.