Bichon Posted October 20, 2007 Report Share Posted October 20, 2007 which kelvin rating is better for growing plants? 6500k or 10000k would I have alot of algae growth if I use 10k? would the colour of fish in the tank look gaudy? Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted October 20, 2007 Report Share Posted October 20, 2007 It is a matter of personal choice and what works for you. Blue light---small K makes plants shorter and compact. Red light--- larger K makes plants rank and skinny. I use growlux (3500K) and soft white (2700k) as well as about 1/10 of the wattage in incandescent. It is what I used 30 years ago and the sun has not gone behind a cloud permanently---works for me. Others swear by daylight ---6500K. You pays your money and you takes your pick. Some of the salties might advise but I suspect 10000K is more for marines. Quote Link to comment Share on other sites More sharing options...
jayci Posted October 20, 2007 Report Share Posted October 20, 2007 alanmin, Do you use the 3500k and the 2700k together? Or seperate? I am needing to build a light hood and the 2700k bulbs or tubes are easy to find, and also cheap. Quote Link to comment Share on other sites More sharing options...
nemines Posted October 20, 2007 Report Share Posted October 20, 2007 10000k is what i got on my nano reef - probably not the best for plants...might encourage too much algae growth Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted October 20, 2007 Report Share Posted October 20, 2007 Most people seem to use daylight tubes (6500K) but I have best luck with a growlux (3500K) and a soft white (2700?) and a small incandescent that goes all the time so the fish don't get such a fright when the lights come on. Quote Link to comment Share on other sites More sharing options...
Bichon Posted October 21, 2007 Author Report Share Posted October 21, 2007 thanks alot alan and nemines Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted October 21, 2007 Report Share Posted October 21, 2007 I use both tubes together and find 2 x 4 footers best and left on 17 hours/day. That tank is 400mm high. I have another that is 500mm high with 2 x 3 footers on 17 hours/day and it grows many plants well but doesn't get enough light to the bottom of the tank for small plants. Quote Link to comment Share on other sites More sharing options...
jayci Posted October 22, 2007 Report Share Posted October 22, 2007 So If I want to grow glosso, I'll need 4 tubes to get the light output? Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted October 22, 2007 Report Share Posted October 22, 2007 It depends on how high the tank is. 2 x 4 footers is good on 400mm high and 2 x 3 footers is not enough for the bottom of 500mm high. I can't tell you about glosso---I grow it emersed. Quote Link to comment Share on other sites More sharing options...
Bichon Posted October 22, 2007 Author Report Share Posted October 22, 2007 If I want to keep ricca at bottom of the tank I would need 6500k tube? Quote Link to comment Share on other sites More sharing options...
Luke* Posted October 22, 2007 Report Share Posted October 22, 2007 lol I've just started doing that tonight. Using a 6500k metal hallide bulb (400w). It's more the wattage than the lighting temperature (kelvin) that is important. 6500k gives a nice daylight look to everything. The lower numbers sound interesting too so might have to try those some day. Riccia needs a lot of light if it's on the bottom as it actually a floating plant. Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted October 22, 2007 Report Share Posted October 22, 2007 If you put the growlux to the front it will make cardinals or neons look realy good as it enhances red and blue. As stated, it is the intensity of light that matters. Luke has 400 watts and I have 80 watts. You pays your money and takes your pick. With metal halides you pays your money and you keeps paying. Quote Link to comment Share on other sites More sharing options...
nemines Posted October 23, 2007 Report Share Posted October 23, 2007 alan, why do you leave your lights on 17 hours a day? Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted October 23, 2007 Report Share Posted October 23, 2007 To make the planks grow. Quote Link to comment Share on other sites More sharing options...
Bichon Posted October 23, 2007 Author Report Share Posted October 23, 2007 Hi alan leave your lights on 17 hours a day!!! algae problem? How you keep the algae under control alan? Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted October 23, 2007 Report Share Posted October 23, 2007 It is not usually a problem. What about the people running hundreds of watts of metal halides. Quote Link to comment Share on other sites More sharing options...
Hoody Posted October 24, 2007 Report Share Posted October 24, 2007 I have a 70cm high tank and am struggling to get light to the bottom and it kinda looks a bit shadowy down there? Any idea's for bulb's?? I've got a 10000k 20w and a 18000k 20w (T8's) at the moment. Tank is planted but I dont know a great deal about bulb's? Quote Link to comment Share on other sites More sharing options...
nemines Posted October 24, 2007 Report Share Posted October 24, 2007 the people with halides though, they usually match the plants light needs with lots of nutrients and co2 AND they only have the lights on for about 10 hours! 17 hours a day isnt that natural is it? the founders of the dupla company kaspar horst and horrst e. kipper say that "we should like to recommend 30 to 50 lumen per litre of water in the Optimum Aquarium....the recommended lighting time of 10 to 12 hours SHOULD NOT BE EXCEEDED as it disrupts the natural bio-rhythm of the tank..." and having the lighting on for fewer hours means that they last longer too! Quote Link to comment Share on other sites More sharing options...
Zev Posted October 24, 2007 Report Share Posted October 24, 2007 I have a 70cm high tank and am struggling to get light to the bottom and it kinda looks a bit shadowy down there? Any idea's for bulb's?? I've got a 10000k 20w and a 18000k 20w (T8's) at the moment. Tank is planted but I dont know a great deal about bulb's? I think you will struggle to get good light at 700mm, even with MH the light penetration for good plant growth on the bottom may not reach down that far. 500 - 600mm seems to be the prefered depth. Even marine tanks with their 250w and even 400w Metal Halides are usually around 600mm in depth. As *Luke said, the wattage of the light determines how much light you will get, the Kelvin Temperature determines the colour of the light. Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted October 24, 2007 Report Share Posted October 24, 2007 You have the wrong K ratings for plant and it is too tall for small bottom plants. Large plants like E uraguayensis would be OK because they could get light from the top. You will have a struggle to grow plants near the bottom. Quote Link to comment Share on other sites More sharing options...
Hoody Posted October 24, 2007 Report Share Posted October 24, 2007 As *Luke said, the wattage of the light determines how much light you will get, the Kelvin Temperature determines the colour of the light. You pretty much answered what I was trying to ask?! :oops: Ha ha I do get ok light at the bottom and plant's are growing well, nut just dont get that "brightness" I'm looking for. I'll have a play around with some different type's of bulb's I think?! Quote Link to comment Share on other sites More sharing options...
Zev Posted October 24, 2007 Report Share Posted October 24, 2007 Flourescents give an even light across the length of the tube, it is quite a 'bland' effect (can you tell I hate flourescent light fittings in kitchens?!) Metal Halides, give a more directional light, so if you have no intricate or large diffuser - such as a Lumenarc diffusers, which are 400mm square - behind the lamp, the brightest area will be directly under where the lamp burns, and the brightness will taper out towards the edges. Metal Halides also give a nice 'movement' or 'play of light' on the plants and substrate of the tank if you agitate the surface of the water. Quote Link to comment Share on other sites More sharing options...
nemines Posted October 24, 2007 Report Share Posted October 24, 2007 the wattage doesn't determine how much light you'll get. the watt per litre rule has become incorrect due to different kinds of lighting. 'lumen' is used to indicate the greatest light strength of all lighting methods. watts are only really important when ligthing methods are being installed, since it shows economy and effectivity. e.g. metal halide lamps tend to have 75 lumen per watt, lumilux fluororescent lamps have 95 lumen per watt. i believe the t5 HO lifegro 36w has approx 76 lumen per watt. As *Luke said, the wattage of the light determines how much light you will get, another example a normal incandescent light bulb of say 150w. a lot of that wattage is actually converted into heat. therefore clearly it is the lumen which are important. but at the end of the day it all comes down to what plants you wish to grow, researching their requirements and then growing them. if your tank is 700mm then you could try maybe floating plants or plants attached to driftwood like anubias and java fern. most metal halide lamps can be used for tanks up to 100cm deep without any problem. the reason why so many reefers go for tanks 60cm or less it because their corals need extremely high lumen for zooxanthellae to grow and having a shorter tank means that they can keep such specimens, the lighting needs of these corals enormously surpass those of most plants. Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted October 24, 2007 Report Share Posted October 24, 2007 Most people use watts because that information is more readily available than lumens which realy requires a meter which most don't have. What you say is true of course. Quote Link to comment Share on other sites More sharing options...
purplecatfish Posted October 25, 2007 Report Share Posted October 25, 2007 One day we will be able to buy lamps that have PUR (photosynthetic usable radiation) ratings in order to work out which is best for us. Wattage, colour temp and relative spectrum graphs don't give us the best information to make our judgements. The colour temp is a rating based on our eyes which have a peak in the green. Plants however are interested in the red and blue parts of the spectrum, which is why the best plant bulbs appear purple. Quote Link to comment Share on other sites More sharing options...
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