Fay Posted January 24, 2005 Report Share Posted January 24, 2005 I have 4x250w Metal Halide lamps: When should I replace the bulbs? Quote Link to comment Share on other sites More sharing options...
Brianemone Posted January 24, 2005 Report Share Posted January 24, 2005 when you have the $$$$ they say every year the bulbs need replacing Quote Link to comment Share on other sites More sharing options...
RnB Posted January 24, 2005 Report Share Posted January 24, 2005 its an interesting one, given the ammount of evidence that the spectrum printed on the bulb does not have a great deal to do with the test results. Even if the spectrum moves, is this matterial, or is it simply that the par levels fall off........ Quote Link to comment Share on other sites More sharing options...
Pies Posted January 24, 2005 Report Share Posted January 24, 2005 I have been replacing my 250 watt 10k BLV bulbs on 9 month cycles. I run my bulbs for 10hrs a day. The visible difference is noticable, but not huge. The reaction I get from the coral is huge, often starting growth outbreaks and increased colour. I changed my T5s just recently after 11 months of use. The difference here was HUGE is visible difference. The blues are so much brighter than they were, a massive improvement. Pie Quote Link to comment Share on other sites More sharing options...
jetskisteve Posted January 24, 2005 Report Share Posted January 24, 2005 If you want hair algae follow Brians advice I change mine about every 9 months too. Quote Link to comment Share on other sites More sharing options...
RnB Posted January 24, 2005 Report Share Posted January 24, 2005 I hear this said a lot steve, but is there any "real evidence" that the spectrum changes so far that it causes (or indeed can) cause hair alagae outbreaks... is it the change in intensity that causes the problems? I know sanjay is trying to get old bulbs to do tests on, I await his scientic results eargerly Quote Link to comment Share on other sites More sharing options...
Brianemone Posted January 24, 2005 Report Share Posted January 24, 2005 whos sanjay?? i have noticed a huge reduction in unwanted algae since i changed bulbs earlier in the month, my results are alittle tainted though because i also added a skimmer :-? oh well but it looks alot better, and that alon ewas worth it Quote Link to comment Share on other sites More sharing options...
chimera Posted January 24, 2005 Report Share Posted January 24, 2005 i'll be changing my m/h bulbs in the next couple of weeks too. whats the general consensus now for the best spectrum? 10k, 12k, 15k, 20k? considering i have very few blues, i was thinking slightly higher in the spectrum, say 12k or 15k. is this too intense? pies didnt you get 15k's recently? Quote Link to comment Share on other sites More sharing options...
RnB Posted January 24, 2005 Report Share Posted January 24, 2005 SANJAY JOSHI http://www.advancedaquarist.com/issues/oct2004/reviewb.htm Discussion and Conclusion Figure 15, and 15 show comparison of power and PPFD of the various lamps tested. Once again as seen from the data and plots, there is wide variation among the lamps and the use of CCT to designate the lamps is pretty much meaningless given that the spectral plots are often very similar yet the lamps are being sold with different color temperatures. The usual disclaimer applies - this data is based on a sample size of one, and we have no idea what the variation is within lamps. The HQI 80 ballasts tends to consume much higher wattage than the rated 250W, while the electronic ballast tends to stay close to the rated power of the lamp. The implications of consuming more power are obvious - more light output, however if this detrimental to lamp life remains to be seen. Comparing the data here and other 250W DE articles with the data for 250W Mogul lamps, should provide enough factual information to dispel the myth that 250W DE lamps produce more light output than the 250W single ended mogul lamps. A general sweeping statement to this effect cannot be made, and depends on the lamp under consideration. Quote Link to comment Share on other sites More sharing options...
lduncan Posted January 24, 2005 Report Share Posted January 24, 2005 i'll be changing my m/h bulbs in the next couple of weeks too. whats the general consensus now for the best spectrum? 10k, 12k, 15k, 20k? considering i have very few blues, i was thinking slightly higher in the spectrum, say 12k or 15k. is this too intense? pies didnt you get 15k's recently? Hard question. Kelvin ratings are not standard across all manufacturers. Trial and error seems to be the way to find the bulb you like best. Everyone's taste is different. Layton Quote Link to comment Share on other sites More sharing options...
Pies Posted January 24, 2005 Report Share Posted January 24, 2005 whats the general consensus now for the best spectrum? 10k, 12k, 15k, 20k? considering i have very few blues, i was thinking slightly higher in the spectrum, say 12k or 15k. is this too intense? pies didnt you get 15k's recently? There seems to be some conjecture about what 12k vs. 14k vs. 20k really means. From what i've been reading it really breaks down into 6500k, 10k and 20k (blue). So 12k, 15k and 20k should be called blues as they will be in the 20k spectrum. There is no doubt that many manifactures are using all these different turms, but the colour of a bulb should not be confused with the kelvin (colour tempratue) of the bulb. I've been using 10k for 2 years, am switching to blues (radium) for all 4 MHs. Personal aesthetic reasons for now. I am suplimenting with 2x blue T5s and 2x white T5s. I am also considering adding 1 or 3 white MH 400/250s to do a 'high noon' simulation and just run them for say 2 hours a day. I am also not sure if I will keep the T5s, currently I am 50/50 of their nessessity in my system. Hope that helps and makes sense? NOTE: Blue MHs make the water look so much clearer and crisper than with the 10ks. Less reflection off the bubbles and anything else setteling in the water. If you have a look at the latest pics of my tank you will see 2x Radium Blues at the right and 2x BLV 10ks on the left. Pie Quote Link to comment Share on other sites More sharing options...
RnB Posted January 24, 2005 Report Share Posted January 24, 2005 to quote agian Once again as seen from the data and plots, there is wide variation among the lamps and the use of CCT to designate the lamps is pretty much meaningless given that the spectral plots are often very similar yet the lamps are being sold with different color temperatures. its a matter of what you like.... advertised colours not backed up in the lab. I have a 10K on one end and a 14k on the other, the 14k is a LOT bluer. Personally I now like the 10k's more then the 14k's Quote Link to comment Share on other sites More sharing options...
chimera Posted January 24, 2005 Report Share Posted January 24, 2005 hmmm, hard to tell from your picture pies - you can see a very subtle difference - probably need to see it in person to make a honest judgement. however personally i tend to like a blue more than a white in water (more "oceanic" ) aside from that i trust and value your judgement (that the radiums look better - and perhaps more so on a larger tank) so will probably go with those. Quote Link to comment Share on other sites More sharing options...
Pies Posted January 25, 2005 Report Share Posted January 25, 2005 Chimera - I thought I had posted a different picture, i'll post one when I get home, the difference between the blue and the white is quite obvious. Maybee some of the other people where were at my place the other week for the BBQ would care to comment. I currently have 250-10k 250-10k 400-blue 400-blue. Tonight I hope to replace with 400-blue 400-blue 400-blue 400-blue. Will take some photos for you to have a look at, do some comparisons. will also take some photos with the T5s in various states of suplimentation. The blues are less 'intense' in that they output less light, so more may be needed to get the same as from 10ks or 6500ks. As stated am still considering adding in 1 or 3 extra bulbs for 'high noon' type killer light That way I know I will have the whole spectrum covered Piemania Quote Link to comment Share on other sites More sharing options...
chimera Posted January 25, 2005 Report Share Posted January 25, 2005 where did you end up getting your lights from? did you do diy styles, get them made up or purchase new/2nd hand? i only have 2 x 250W M/H's on the tank and feel like I need one more in the middle (whether that be 250W or 400W) to cover the entire tank nicely. also what sort of $$$'s if you dont mind me asking? Quote Link to comment Share on other sites More sharing options...
Pies Posted January 25, 2005 Report Share Posted January 25, 2005 I purchased Ballasts from Radium Lighting in Auckland. The ballast, wired to a 3 pin plug including box, with the 3 pin (round plug) earthed lead cost less than $150.00 incl GST. Add a bulb holder (mogel e39/e40) for about $17.00ea. Bulbs are Radium Blue cost under $150ea. I got a good deal as I purchased 4x, so not sure what the normal list price is. When I had my 5 footer (1600mm long 750mm wide) I had 2x 250watters, It needed 3x. The problem was that I had the center brace made from glass so i couldn't really do 3 bulbs, but the tank suffered for it. My new tank is 7 feet long and has 4 bulbs on it. Piemania Quote Link to comment Share on other sites More sharing options...
Drifty Posted January 25, 2005 Report Share Posted January 25, 2005 do you need /have glass covers for your lights pies. what sort of reflector did you use Quote Link to comment Share on other sites More sharing options...
chimera Posted January 25, 2005 Report Share Posted January 25, 2005 Pies - can you put some pic's of your lighting system up? 3 m/h's makes sense so i wouldnt mind adding another m/h to the system to cover the middle - perhaps even 250W's on the outside and 400W in the middle to give it a slightly blurred out effect?! the centre brace is only about 4 inches wide so should be ok (and the extra wattage will help in the middle through the brace). i've put most corals in such a location that those that need most light are directly below the centre of the m/h's anyway. Quote Link to comment Share on other sites More sharing options...
Pies Posted January 25, 2005 Report Share Posted January 25, 2005 I've posted photos on my 'first look thread', shouldn't take over this one. Drifty I am using single ended bulbs so no need for cover glass as the outer sheild is the 'cover' glass. NOTE: You must use cover glass for doubble ended Metal Halides. My reflector - VERY DIY at the moment. Its a bent stainless steel reflector 2 metres long. There are some pictures of it on an earlier thread I had running about lighting. If you can't find it let me know and i'll search around. Pretty ordenarty stuff but its all I can do (afford) right now. Pie Quote Link to comment Share on other sites More sharing options...
Fay Posted January 25, 2005 Author Report Share Posted January 25, 2005 Picking up the new lamps tomorrow, sticking with 250w 14k and replacing the florros<> gunna cost a packet!!!! Also changing one of the t5's in the small tank with another white to blue on one side. Quote Link to comment Share on other sites More sharing options...
Pies Posted January 25, 2005 Report Share Posted January 25, 2005 Fay - Yeah its expensive. I have factored bulb replacement costs into my overall costs and its the reason I went for 4x 400 watt over 6x 250 watt. similar power costs, but bulb replacement would have killed me. At least all of my bulbs are new right now, 9 months of worry free lighting Good luck Pieman Quote Link to comment Share on other sites More sharing options...
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