VinsonMassif Posted January 18, 2008 Report Share Posted January 18, 2008 Is there a way to calculate the degrees kelvin of a flouro tube from the stated lumens? I was browsing the tubes in a couple of places but the degrees kelvin is not usually listed. I was mainly looking at Phillips or Osram sylvania tubes..... I googled but didn't find what I was looking for. I also visited the manufacturers websites which also didn't tell me what I was after... And as per usual the staff seemed inadequately educated as to the products the stores stocked, standing around with vacant expressions being entirely unhelpful. Quote Link to comment Share on other sites More sharing options...
VinsonMassif Posted January 19, 2008 Author Report Share Posted January 19, 2008 Ok so I found out there is no relation at all between Lumens and Kelvin. But the number after the watts indicates kelvin. ie. 38W/865 = 6500k. Quote Link to comment Share on other sites More sharing options...
Zev Posted January 19, 2008 Report Share Posted January 19, 2008 Have a look here, I know it's an offshore retail site, but it gives some info on the colour temp of the tubes they stock, which are mostly Phillips so the specs should be the same as the ones we get here. http://www.bulbs.com/T--8_Linear/results.aspx Quote Link to comment Share on other sites More sharing options...
VinsonMassif Posted January 19, 2008 Author Report Share Posted January 19, 2008 Thanks Zev. Quote Link to comment Share on other sites More sharing options...
VinsonMassif Posted January 19, 2008 Author Report Share Posted January 19, 2008 A further thing I found out about the number after the wattage was that the first number is the version number of the tube. ie. 735 = 7th version & 3500k; 835 = 8th version & 3500k. Did everybody else know this stuff? Quote Link to comment Share on other sites More sharing options...
evilknieval69 Posted January 19, 2008 Report Share Posted January 19, 2008 Did everybody else know this stuff? Yep Quote Link to comment Share on other sites More sharing options...
VinsonMassif Posted January 20, 2008 Author Report Share Posted January 20, 2008 Yep Is there an article or stickied topic I somehow missed in my search listing what you should know when starting setting up lights for a successful planted tank? Quote Link to comment Share on other sites More sharing options...
Adrienne Posted January 20, 2008 Report Share Posted January 20, 2008 Yep No - I'm totally confused, have no idea how to work out my lighting - what I have oOR what I need :oops: Quote Link to comment Share on other sites More sharing options...
evilknieval69 Posted January 20, 2008 Report Share Posted January 20, 2008 Is there an article or stickied topic I somehow missed in my search listing what you should know when starting setting up lights for a successful planted tank? Not realy, i wrote a bit of an article about planted tanks (link in my signature) but i dont think i realy went into light details very much Have a read of it anyway Quote Link to comment Share on other sites More sharing options...
VinsonMassif Posted January 20, 2008 Author Report Share Posted January 20, 2008 I feel similarly. When I have read articles/threads about what lighting a planted tank does best in it seems 1.5-2.5 watts per gallon is a recommended range. Also 6,500 degrees kelvin is optimum. I would like to know more about optimum depth of a tank taking into consideration light dispersal. I have read deeper than 600mm is pushing it. But at which wpg ratio? If your tank is 600mm deep how many watts gives you successful light dispersal for plants which require medium-high light? I read an old thread about Atman lights 10,000-15,000k which are typically used over marine tanks. If used over freshwater how efficient are these bulbs for plants growth seeing as they are such a high kelvin rating. Do the plants benefit from >7,000k or is it wasted on them seeing as they photosynthesize at 630nm, 700nm? If you uses Gro-lux bulbs they lack the middles light spectrum which makes your tank appear dimly lit. Store clerks merely told me the listed lumens of a specific length bulb. The manufacturers website has the products listed, but there are hundreds of them - leading to more confusion than understanding. Seeing as Phillips Cool Daylight 48" 36W tube is 6,500k and cost $4.90 from Mitre10 mega, why are the bulbs at LFS $40 odd? Just pondering, would like to know. I don't mean to sound like I am complaining. Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted January 20, 2008 Report Share Posted January 20, 2008 You do sound like you are complaining and why not. The present fashion is to use 6500k lights. 30 years ago we used a combination of growlux and cool white with 1 tenth of the wattage in incandescent. Before that we used incandescant and before that candles. I used 6500 tubes for a year and have gone back to growlux/cool white. The flower growers use 6500 metal halides. You pays your money and you takes your pick. I grow a lot of plants and have no tanks over 500mm deep and try to duplicate conditions which the average punter might have. I therefore do not grow some plants submersed such as Ludwigia perennis or arcuata, or Rotala macrandra even though I may grow them emersed. Lighting is more related to water depth than litres, and lighting can be increased by leaving the lights on longer. Quote Link to comment Share on other sites More sharing options...
VinsonMassif Posted January 20, 2008 Author Report Share Posted January 20, 2008 Thank you all. I appreciate it. I think I will try my hand with PMDD too Quote Link to comment Share on other sites More sharing options...
VinsonMassif Posted January 20, 2008 Author Report Share Posted January 20, 2008 In my travels I found an interesting article on Lighting, specifically Lighting for plants. There is a lot of info, but quite interesting. http://retirees.uwaterloo.ca/~jerry/orchids/light.html Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted January 21, 2008 Report Share Posted January 21, 2008 Lighting for emersed plants is different to lighting fo submersed plants. In China I understand that they use daylight (6500k) energy saving bulbs to grow plants emersed. Blue light makes plants compact and red light makes them tall and skinny. I grow many plants emersed then convert them to submersed and they can be quite different. E. uraguayensis in my aquarium has leaves about 700mm long and a mature emersed plant would be lucky to exceed 70mm. When trying to keep emersed plants over winter I have found that some plants do well under artificial light and others are pretty suicidal. You pays your money and you takes your pick. Quote Link to comment Share on other sites More sharing options...
Robert Smith Posted January 31, 2008 Report Share Posted January 31, 2008 Vinnie, You're quite right, the W/L (watts per litre) guide is not good enough! We need a W/m2/m standard (Watts per square metre of surface area per metre of depth). The caveat will be a maximum W/m2, otherwise any fish that surfaced in a 1m deep tank may find her eyeballs fried in her head. Can anyone give us the dimensions of the tanks where the !/L guide comes from? It should be easy enough to covert from there. How much is too much? Bob Quote Link to comment Share on other sites More sharing options...
VinsonMassif Posted January 31, 2008 Author Report Share Posted January 31, 2008 Robert from what I have gathered from reading various forum threads and articles is this: - Plants in a typical FW setup do well in 2 WPG if they are less than 700mm deep, being planted in suitable substrate, and including plant supplements regularly. - CO2 addition is not always necessary: http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm - Plants flourish in 6500-7500k range. More than this is not natural for plant photosynthesis. ie. using marine lights rated at 10,000-15,000k in a FW tank. - Also if you use >2 WPG you don't need your lights on for as many hours each day. So I decided that by using Cool Daylight 36W/865 in conjunction with Gro-lux bulbs my plants are getting their light needs at 2 WPG, 600mm deep. I use Flourish Iron, and Excel daily, and have Dalton's aquatic mix clay under my sand substrate. My plants are growing like mad and looking great. Some new plants I have planted are growing an inch per day, and my red swords have coloured up nicely. On a side note Actinic tubes are great for bringing out the blue colouring in fish. Quote Link to comment Share on other sites More sharing options...
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