I am inclined to agree with Steve (an unusual happening) Actinics should be used to adjust the color of the tank. As such the bulb will lose some intensity over time, but as it is only supplemental lighting there is no reason to rush out and replace the bulb. :rolleyes:

when using VHO for actinic only???? thats what we are talking about using VHO for actinics and MH for main lights.



Steve

Sorry, I thought the issue was about using VHO's as the main lighting source.

Rick

partially, guess I should say the present discussion was for that( my apologies), but originally it was for using them as sole lighting on lower light tanks. how long did you find they lasted?
I am looking for a way to light a softy/LPS tank myself and I am considering not using MH for this one. but then again I might anyways. but actinic is my real question for these T5's I have PC's on my little one right now and would like a bit more actinic on it.

Steve

Using T5's as a sole lighting system, I found that the tank quality took a turn for the worse at 6mo. This included an increase in algae growth in the forms of green hair and the green stuff on the glass. After around the 8mo. mark my corals closed up more often and the fast growth rate that I initially had dropped off to almost nothing. I changed the bulbs at this point.

I used T5's only because I couldn't afford a full lighting system up front and the T5's allowed me to expand as my budget allowed. If I had to do it again without using halides, which is what I currently run, I would run power compacts. This is solely due to the fact that you have to replace them less often.

If you can afford the halide and you already have the PC's, why don't you make those actinic and throw on a bluer halide, say a 20K? You won't have the same replacement cost as is associated with a full compliment of PC's

Rick

I am not sure if this thread is not deteriorating into the old often heard arguments. I do want to say I was a PC fan for a long time, but when I actually measured the lumen output I found a decrease of 50% at six months. That to me was unacceptable. :sad:

thats horable Bob, out of the 8 PC's I have has the wose was 12% at 6 months and 22% at 1 year. I found that at about 16 months they drop again sharply.

Steve

Lights are on their way. I'll post when i try them out.

Walter

Steve the 24 inch are 23 1/4 overall. They also came in 36, and 48 if you need overall leng of the other size I will measure them for you

Maybe it depends on the bulb or the ballast overdriving/underdriving the bulb? When I had 55W GE9325K bulbs running on the Workhorse ballast, there was a very noticeable decrease in visual light after 6 months. My purple cap would turn brown by the 6 month mark and would turn purple again again changing bulbs.

As for Actinics, I measured my dissolved oxygen levels with only the 95W VHO Actinics powered on. There was very little increase in oxygen which leads me to conclude that not much photosynthesis was going on under 95W of Actinics. There was slightly more DO under the 96W 50/50 bulb. And of course, there was significantly more under the MH.