maran Posted December 19, 2006 Report Share Posted December 19, 2006 I have 2 double tube light holders at the moment. I am wondering of mixing up the colours to get the best. What should I go for. ( I think I got somethink like 14000 K colour ones with the light when i bought it, but not happy with it ( I have a fresh water tank) I know 6500-7000 daylight white is good for plants. so i am planning to get 2 off them. Still 2 more speces letf. Any other colours good for plants. Colour that best shows fish colours? Quote Link to comment Share on other sites More sharing options...
evilknieval69 Posted December 19, 2006 Report Share Posted December 19, 2006 Personally, I would have two 8000K bulbs for the plants, a 10000K bulb for looks on the fish, and a 14 or 20000K bulb for moonlighting... thats how i would have it anyways...... Quote Link to comment Share on other sites More sharing options...
maran Posted December 19, 2006 Author Report Share Posted December 19, 2006 Whats moonlighting? Is it to leave the light on at night? I also heard that plants like 2 different spectrums of light (photosynthesis happens best at these 2 spectrums-so one is 7000K. What is the other?) Quote Link to comment Share on other sites More sharing options...
DiverJohn Posted December 19, 2006 Report Share Posted December 19, 2006 Well i have my own opinion on "the best light for fish colours", and it's quite simply as close to daylight as you can get. Ie: 5000-8000K. Having seen many tanks and lots of photo's where people say "why dont my fish colours stand out" i have to say that IMO the biggest culprit in making fish colours 'bland' is that damned 'pea soup' gravel the LFS supply. Its got too much white pebble in it. And that white pebble is reflecting light straight into your eye... making it look washed out. Remember fish evolved over millions of years to camoflaged to predators, alot of whom, look down from above. So think like a fish. If you where swimming around on a white ( or light coloured) background would you turn your full colours on ??? For my $0.10 I would first spend $15 and get some nice dark substrate, Dalton propagating sand would be ideal, with the added bonus your plants will love it! Then just get some daylight tubes from bunnings. Quote Link to comment Share on other sites More sharing options...
evilknieval69 Posted December 19, 2006 Report Share Posted December 19, 2006 moonlighting doesnt do anything at all realy. it is just for your viewing pleasure. People often have the moonlights switch on after the main lights go out, and stay for half an our or so, just so you can see the fish under a 'cool' blue effect, watching their night procedures. It probably settles the fish down for bed aswell.... Quote Link to comment Share on other sites More sharing options...
evilknieval69 Posted December 19, 2006 Report Share Posted December 19, 2006 I also heard that plants like 2 different spectrums of light (photosynthesis happens best at these 2 spectrums-so one is 7000K. What is the other?) uhhhh, nope?!?! :lol: Plants do best under exact sunlight, so in the aquarium we try and replicate the light ratings of the sun, to get the best plant growth and looks. 6500K is white, being very close to the suns rays in colour etc. But IMO, plants and fish, and general viewing of the tank look best under 8000K or thereabouts.... And about the moonlighting... Is it to leave the light on at night? You should never leave any light on all night, fish need to sleep, just like we do. HTH Quote Link to comment Share on other sites More sharing options...
Aquarium Dude Posted December 19, 2006 Report Share Posted December 19, 2006 Out of interest, how long is your tank Quote Link to comment Share on other sites More sharing options...
maran Posted December 19, 2006 Author Report Share Posted December 19, 2006 It is 150cm by 60cm by 60 cm. Quote Link to comment Share on other sites More sharing options...
Warren Posted December 19, 2006 Report Share Posted December 19, 2006 As someone else mentioned here recently, it's not the K rating that's most important, it's the colour rendering index (CRI). Natural equatorial midday sunlight has a CRI of 100. So the closer you get to this, the more natural the fish colours (and plant colours) will be. For fluro's, about the closest you'll get is colour 96 from Philips or Sylvania TLD96 series lamps. They have a K rating of 6500 and a very natural look. They do not artificially enhance the reds or blues like some other lamps. It really comes down to the look you want and that's entirely personal preference. For plants, go for 6500K colour 96 lamps. 14000K will make things pink and enhance the reds and blues but will not look natural but have a nice effect (that's what happens when you mix red and blue - you get pink). Typically the higher the K the more blue it gets. Watch out the high K lamps - they tend to cause algae in freshwater tanks. Quote Link to comment Share on other sites More sharing options...
shiuh Posted December 19, 2006 Report Share Posted December 19, 2006 sorry out of topic here. what about for saltwater tanks? a typical K range will be 10000K to 14000K? Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted December 19, 2006 Report Share Posted December 19, 2006 Does the K rating or CRI change as the tube gets older? Quote Link to comment Share on other sites More sharing options...
DiverJohn Posted December 19, 2006 Report Share Posted December 19, 2006 Sorry to be a predantic Alan but no the 'rating ' is written on the tube :lol: :lol: google seach with key words: fluorescent tubes age spectrum Basically yes... they tend towards the warmer colours Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted December 19, 2006 Report Share Posted December 19, 2006 But the rating is not so that all the light emitted is of that stated frequency. If you look at graphs they show a range of frequencies around that stated. I was asking if that changed with age. Quote Link to comment Share on other sites More sharing options...
richms Posted December 20, 2006 Report Share Posted December 20, 2006 But the rating is not so that all the light emitted is of that stated frequency. If you look at graphs they show a range of frequencies around that stated. I was asking if that changed with age. Yes, some of the phosphers will age faster then others. If you are the type of person that keeps tubes in untill they no longer strike anymore then you are well past when they should have being replaced, if you change them at the end of their useful life then the spectrum shouldnt have changed too much from new. I try to relamp my t8's anually, more for peace of mind then anything else. Quote Link to comment Share on other sites More sharing options...
maran Posted December 21, 2006 Author Report Share Posted December 21, 2006 Coming back to Kelvins and CRI: My understanding is the Kelvin of a Tube light is the peak of the spectrum it emits ( Example is a 6500K tube light emits light ranging from 1000K to 20000K, but most the colour it emits is at the colour 6000-7000). CRI is the how close it resembles the true sun light! Is that right? From above I would presume, that a light with 6500K ( apparently closest to normal day light colour) and CRI of 965 (96.5% comparable to day light sun light), would be emiting nearly "true" sunlight, with the peak colour of 6500K. Is that mean even normal sunlight we get at noon has a widespectrum of colours, but mostly concentrated at the middle (6000-7000). Correct and explain if I am wrong. I might be way off the truth! More questions will come after I get above sorted :roll: Quote Link to comment Share on other sites More sharing options...
richms Posted December 21, 2006 Report Share Posted December 21, 2006 The 9 in 965 just means that it is above a 90 CRI, the 65 is the 6500K part, I think most tubes get a cri of 91, so barely scraping into the 90s. They also look very very purple and cost heaps more then an 865 tube does, and have lower light output. Stick with 865 tubes is my advice. Quote Link to comment Share on other sites More sharing options...
Warren Posted December 21, 2006 Report Share Posted December 21, 2006 The datasheets for the TLD96 state they're colour 98, not 90.5 They are quite superior to the TLD86. I've used both and set side by side it's easy to see the difference. It's like the difference between a 3 and 5 phosphor tube. Product Description: TL-D 90 GRAPHICA PRO 36W/965 SLV/10 Commercial Code: TLD36W965 Bulb Shape T8 Bulb Finish - Watt (W) 36 Volt (V) - Cap Base - Color Temperature (K) 6500 Lumen (Lm) 2100.0 Beam Angle (o) - Line Frequency (Hz) - Color Rendering Index (Ra) 98 Color Descriptions 965 COOL DAYLIGHT Average Life Hours - Quote Link to comment Share on other sites More sharing options...
Warren Posted December 21, 2006 Report Share Posted December 21, 2006 Compared to: Product Description: MASTER TL-D REFLEX 36W/865 SLV/25 Commercial Code: TLD36W865REFLEX Bulb Shape T8 Bulb Finish CLEAR Watt (W) 36 Volt (V) 220 Cap Base G13 Color Temperature (K) 6500 Lumen (Lm) 3350.0 Beam Angle (o) - Line Frequency (Hz) 50 Color Rendering Index (Ra) 85 Color Descriptions 865 COOL DAYLIGHT Average Life Hours - As richms said though, they're lower lumens/W so you'll need more... Quote Link to comment Share on other sites More sharing options...
richms Posted December 21, 2006 Report Share Posted December 21, 2006 I bought some 965s for the office a few months back... not a patch on 865s for brightness, infact it was not enough, i would have needed tripple tube fittings to get it up to being workable. Quote Link to comment Share on other sites More sharing options...
Ira Posted December 21, 2006 Report Share Posted December 21, 2006 So, not only are they almost 40% dimmer so you need to buy more they cost more to buy? I bet they don't last as long either. Might as well just go with MH. Quote Link to comment Share on other sites More sharing options...
DiverJohn Posted December 21, 2006 Report Share Posted December 21, 2006 A few more things to consider. All of those figures will have be generated running the tubes on the best elctronic balasts you can get. Pretty good chance you will be running 'old skool' magnetic ones. Was looking tru some data sheets froom Osram check this out ... a 5ft58Watt 865 Daylight puts out 5000 lumen, and 840 (warm white) = 5200, 965 (biolux) = 3200 Lm and the good old "Floura" - aka Grolux - 2250lm. I have had very good results with a combination of 965's + (865 or 880) 965's are a bit pricier, but the 865s & 880s are cheaper, so on balance still works out at 1/2 the cost of a LSF tube! Quote Link to comment Share on other sites More sharing options...
purplecatfish Posted December 21, 2006 Report Share Posted December 21, 2006 Check this out: http://www.cameraguild.com/technology/kelvin.htm Don't confuse the temp scale (deg K) with the light spectra scale (nm). In basic terms the whole colour temp thing is a one dimensional scale to represent a three dimensional system (white light is 'made up' of red, green and blue). So it's not the best way to look at the effectiveness of lighting. And the spectral analysis graph on the packaging is also often misleading especially when the axis aren't labeled correctly. I've recently changed from the various LFS aquarium lights (I've tried most brands) to some 86's and they look nicer, I haven't seen the colour of the 96's but I'll be trying them out (thanks for the advice Warren and everyone ). I haven't noticed any downsides yet and I'm looking forward to considerable savings as they are less than half price. But from the plant perspective you need to consider chlorophyll a and b absorption spectra. Check this out: http://www.chm.bris.ac.uk/motm/chlorophyll/chlorophyll_h.htm The ideal lamp spectrum for plant growth would be the sum of both. And I've not yet seen the spectral graph of any of the recommended ones. But (to get technical :roll: ) it doesn't take into consideration the secondary photosynthetic pigments which give the various reds we see in some plants. Does anyone know what rating I should be looking at for a pink fluoro bulb to bring out the fish colours? Quote Link to comment Share on other sites More sharing options...
maran Posted December 23, 2006 Author Report Share Posted December 23, 2006 From what purple cat said, instead of having a 6500K light, I could have a 1800K light which emits yellow red spectrum, and a 10000+ K light which will emit blue/violet colour. Both colours will supply enough light in the spectrum for chlorophil A and B to absorb! Do people mix the 1800K colour and 10000K colour instead of trying to find ONE light at 5000-6500? Another link for interest. http://www.topbulb.com/find/cri.asp Quote Link to comment Share on other sites More sharing options...
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