well, I just got back from Brad's place whare I had the chance to test the 400 watt 20000K radiums on the san agro ballast.. there was some interesting results and ones I didn't expect personaly.
just for some background, the 400 watt Radium on Adams tank (run off of a normal PFO ballast had a PAR value of 343.09 @ 12"
first visualy, the bulbs looked a little more white running on the Son Agro ballast than on the regular PFO ballast
as for actual PAR Values on the new ballast the result was strange.. on the Son Agro ballast it had a PAR value of 356.202 @ 12"
yup almost no increase in PAR. the only explanation I can come up with for this is that maby by overdriving it a bit, it shifts the over all color spectrum up to make it a little more white. In doing this the blue is decreased a bit which drops the PAR levels, as blue is a large player in the PAR game.
just for a reference for people thinking of upgrading there lights, my Ushio 175 watt 10000K MH bulb puts out 262.14 PAR @ 12" so a 400 watt Radium would be a step up, but not as much as I would have expected.
anyways here are a couple comparason pics.. the first one is the Ushio on the left and the Radium on the right. the secon pic is all radium.
as a disclamer it doen't look that "Blue" in person, and I think this is why I have disliked all the pics of radium tanks so far, is that the amount of blue in them plays havoc with digital cameras ( I have to admidt that when I get used to the inital blue haze that there is in real life I actualy find the color pleasing.. so much in fact that I am debating on going this way myself).
The only way you are going to get a nice pic though, is to redo the heck out of it with a photo program or set the white ballance to cancle out the blue and show the true colors as I did on the pics of One_Divided's tank. The only problem with doing this is you do cancle the slight blue haze you would see in real life, but it does give you the "actual" colors of the corals.
so what other conclusing can be drawen from this? well I have a opinion that I will share.. for starters I do not belive going to a radium from another 400 watt bulb will give you better growth, nor do I believe that it will make your corals color up more, what I DO believe is that it is more asteticly pleasing while still providing enough light for good growth, what I also believe is that the large amount of actinic light in the bulb makes the colors stand out more and the corals that have Fluorescent properties it will make them glow a little more with the more intense light.. this would normaly not stand out in a 10000K set up unless you had intense actinic suplament that can over power the white of a 10000K.
anyways that is just my opinions that I have formed sofar and I will quite rambling now so you all can see the post
Steve