bcjm November 16, 2009 November 16, 2009 I have finally switched my 8 T5 to 2 250W MH on a 5'x2' tank. I am using icecap ballasts and pendents with 20K radium bulbs. 1. 8 T5 seem more bright than MH. Not sure if it is because of the color of the bulbs. Do 8 T5 generate about the same intensity of 2 250W MH? 2. I was worry about the heat generated by MH. It is not a problem so far. I don't think it produce more heat than T5. 3. I am thinking to add 2 more bulbs for dawn and dusk. I have the option to go 2 T5 or 2 VHO with icecap 660. Which way would you recommend? 4. 20K bulb is really blue/actinic. Does anyone has some old different kind 15K bulbs I can borrow?
steveoutlaw November 16, 2009 November 16, 2009 I have finally switched my 8 T5 to 2 250W MH on a 5'x2' tank. I am using icecap ballasts and pendents with 20K radium bulbs. 1. 8 T5 seem more bright than MH. Not sure if it is because of the color of the bulbs. Do 8 T5 generate about the same intensity of 2 250W MH? 2. I was worry about the heat generated by MH. It is not a problem so far. I don't think it produce more heat than T5. 3. I am thinking to add 2 more bulbs for dawn and dusk. I have the option to go 2 T5 or 2 VHO with icecap 660. Which way would you recommend? 4. 20K bulb is really blue/actinic. Does anyone has some old different kind 15K bulbs I can borrow? The MH will generate more heat than the T5s so watch you tank temp. If the radium is too blue why not supplement with 3 or 4 T5 blue plus or daylight bulbs? I really like the looks of the MH, but it's all personal preference.
bcjm November 16, 2009 Author November 16, 2009 (edited) The MH will generate more heat than the T5s so watch you tank temp. If the radium is too blue why not supplement with 3 or 4 T5 blue plus or daylight bulbs? I really like the looks of the MH, but it's all personal preference. So far my tank is running cooler with MH. Maybe it has something to do with my T5 was too close to the water surface and all 5'x2' surface with completed covered the the 8 reflectors. Edited November 16, 2009 by bcjm
sportzfish November 16, 2009 November 16, 2009 Was your T5 fixture 4' or 5' long? If it was 5' long then I guess it got better coverage along the entire 5 foot long tank.
bcjm November 16, 2009 Author November 16, 2009 Was your T5 fixture 4' or 5' long? If it was 5' long then I guess it got better coverage along the entire 5 foot long tank. They are 4' bulbs I staggered together. So not all 5'x2' surface are covered. Still, the MH has much better ventilation than my old T5 setup.
amay121 November 16, 2009 November 16, 2009 Just make sure you take before and after pictures. I may want to switch back to MH as well, but still contemplating.
bcjm November 16, 2009 Author November 16, 2009 Just make sure you take before and after pictures. I may want to switch back to MH as well, but still contemplating. My photo skill is not that good. Without proper white balancing the photo does not show the true color.
DDiver November 16, 2009 November 16, 2009 The MH will generate more heat than the T5s so watch you tank temp. If the radium is too blue why not supplement with 3 or 4 T5 blue plus or daylight bulbs? I really like the looks of the MH, but it's all personal preference. adding Blue plus' to supplement Radiums is gonna make it even bluer....
trockafella November 17, 2009 November 17, 2009 I like VHO actinics, i am using them with a 20k MH, i like the color, but very blue... I might go wuth 14k's next time I replace bulbs, just to see if the growth is really better...
Coral Hind November 17, 2009 November 17, 2009 I have finally switched my 8 T5 to 2 250W MH on a 5'x2' tank. I am using icecap ballasts and pendents with 20K radium bulbs. 1. 8 T5 seem more bright than MH. Not sure if it is because of the color of the bulbs. Do 8 T5 generate about the same intensity of 2 250W MH? 2. I was worry about the heat generated by MH. It is not a problem so far. I don't think it produce more heat than T5. 3. I am thinking to add 2 more bulbs for dawn and dusk. I have the option to go 2 T5 or 2 VHO with icecap 660. Which way would you recommend? 4. 20K bulb is really blue/actinic. Does anyone has some old different kind 15K bulbs I can borrow? 1. I have a 6x54w DIY that has slightly more PAR output then the 2x250w 14kK in the mid tank area. The T5 light is spread out more evenly. The bottom of the tank is where there seemed to be a big difference, higher PAR with the MH. I tested both setups with new bulbs. Bulb choices will affect the numbers of course. 2. MH seem to produce more heat because of the radiant energy they give off. That is the same engery that gives them the power to penetrate deeper into the tank. 3. I would go with the T5. There are more color choices and they take up less space. 4. Sorry, I only have 10kK's available.
Origami November 17, 2009 November 17, 2009 1) I looked up your lamp and ballast on Sanjay Joshi's site (Sanjay's Site). His test, taken at 18 inches, show a PAR of 66 umol/m^2-s using 250W Radiums. PAR using 10KK Giesemann's is 95, so you're definitely losing some PAR due to the lamp color. As for comparison with your T5 configuration, I looked up the PAR for ATI Blue Special bulbs (probably the closest to Radiums that you'll get in a fluorescent tube, but still with a rather broad spectrum) at RC's GrimReefer's site (TFiveTesting) and you'll see that the PAR for the bulb is 311 (where Grim takes his measurement at 1" rather than at 18" like Sanjay). Since the measurement is made so close to the bulb, I've assumed that the light that reaches the sensor comes from 1.5" of the bulb length. Thus, I'm estimating that each 48" bulb puts out 30.7 umol/m^2-s at 18 inches. Adjusting for 8 bulbs, that's a PAR of around 245 compared to 132 for the 2x250 20KK Radium MH configuration that you have now. That's assuming 100% reflector efficiency, which is not going to be the case. But it does show why you think your T5's were brighter. 10KK bulbs would, at 190 total PAR put you much closer to what you have now. Also, since MH lamps are typically run much higher off the surface of the water than T5's, you'll have proportionately less r-squared losses from top to bottom in the tank (i.e. less lighting difference between high up and the bottom of the tank). 2. Because MH lamps are typically run much higher off of the tank, you may have more room for air circulation that helps to keep your heat transfer down. If all that heat were trapped in the canopy, the heat of 2x250W lamps (500W) would be nearly the same as 8x54W T5's (432W). Extra air circulation may be helping you out in this regard. 3. T5's. Even though you'll get better actinic performance out of VHO's, you've got enough blue. T5's will give you access to a greater variety. 4. I may have some older 250W bulbs at home. I'll have to look. Grav often has some old bulbs lying around....
bcjm November 17, 2009 Author November 17, 2009 Great information there. Thanks. Let me know if you have any old 15K 250W bulbs.
DJBoy98 November 17, 2009 November 17, 2009 I run a 6-T5 Ice Cap over driven set up. I used to run MH's in my old tank and I think growthwise, they are the same. I like T5's bright look much better. My only complaint is that the purple's are not so purple for me. I have a purple monster and it's starting to finally color up after 3 months of brown but it's more light purple than the deep rich purple I seen from other people. The same goes for my Garf Purple Bonsai.
bcjm November 17, 2009 Author November 17, 2009 I run a 6-T5 Ice Cap over driven set up. I used to run MH's in my old tank and I think growthwise, they are the same. I like T5's bright look much better. My only complaint is that the purple's are not so purple for me. I have a purple monster and it'sstarting to finally color up after 3 months of brown but it's more light purple than the deep rich purple I seen from other people. The same goes for my Garf Purple Bonsai. The reason I switched is because a lot of my corals are turning white, especially the purple. My superman has NO purple. The Bonsai I got from Almon lost all the purple in 2 months. Oregon tort is all white on the body other than purple tips. There are other corals doing the same thing. I don't know what else to do other than changing the lights.
Coral Hind November 17, 2009 November 17, 2009 The reason I switched is because a lot of my corals are turning white, especially the purple. My superman has NO purple. The Bonsai I got from Almon lost all the purple in 2 months. Oregon tort is all white on the body other than purple tips. There are other corals doing the same thing. I don't know what else to do other than changing the lights. I had the same issues with two tanks that are plumbed together, one with 6xT5s and one with 2x250w MH. The orange cap and some acros turned white or very light under the T5s while cutting from the same mother colony in the MH tank kept the color. I reduced the photo period and the color slowly came back. The 6 bulb setup was just to strong for them.
bcjm November 17, 2009 Author November 17, 2009 Based on Origami2547 estimation, I have about half of the PAR value as before. I am running 9-10 hours on MH right now. Not sure if it is enough.
Origami November 17, 2009 November 17, 2009 Based on Origami2547 estimation, I have about half of the PAR value as before. I am running 9-10 hours on MH right now. Not sure if it is enough. Remember, reflector losses can be significant. All the analysis really points to is that it is likely that the PAR is somewhat less than what you had earlier. One large factor in your loss of PAR is the color temperature of the bulb. For example, you can get 50% more PAR out of a Hamilton 10KK bulb, but your light will be on the bright-white to slightly yellow side. Also, ballast selection makes a very significant difference in MH output. Some of the magnetic ballasts seem to produce substantially higher PAR than the electronic ones. Remember, as you go deeper in the water, more and more of the long wavelengths of light are absorbed. The first to go are the reds, followed by orange, yellow and greens. The blues and shorter wavelengths (toward ultraviolet) penetrate further into the water column. By using 20KK bulbs, you're simulating the available spectrum in deeper water. Naturally, there's less PAR there. You may want more light still, but why don't you give it a few weeks and see how everything reacts before making another change? In the end, you may like what you have. It's a configuration that I think a lot of people already use and are happy with. From what I've read though, it is reasonable to expect less growth from 20KK bulbs - though a lot of good things have been said about coral coloration under Radiums.
Almon November 18, 2009 November 18, 2009 3. I am thinking to add 2 more bulbs for dawn and dusk. I have the option to go 2 T5 or 2 VHO with icecap 660. Which way would you recommend? 4. 20K bulb is really blue/actinic. Does anyone has some old different kind 15K bulbs I can borrow? In my 6' main tank, I use 3 x 10K MH for the crisp white look and use 2 x 80w T5 for supplemental actinic support. But I don't like the blue bulbs that everyone else uses. I like the purple bulbs at 460nm. In my 4' frag tank, I have 2 x 20K MH with 2 x VHO for supplemental actinic support. Again, I like the purple bulbs better. 460nm is your friend. The only reason I prefer T5 over VHO is the T5 bulbs use half the wattage. However, the VHO may appear more purple. I would recommend adding either 2 x T5 or 2 x VHO.
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