jetskisteve Posted September 5, 2006 Report Share Posted September 5, 2006 I need to raise mine too just no good at diy Quote Link to comment Share on other sites More sharing options...
puttputt Posted September 5, 2006 Report Share Posted September 5, 2006 I don't think mine are 40cm, but will be more than 20cm. I'll post when I get home. Quote Link to comment Share on other sites More sharing options...
reef Posted September 5, 2006 Report Share Posted September 5, 2006 Funny enough did some testing on a few tanks with my lux meter. Reading was interesting and pretty much as what I have been saying for some time and from anecdotal evirdance from seeing a number of tanks. Tested 3 tanks using 400w lumenarc copies, 14k narva bulbs. All readings taken 20cm from light bulb. Tank one 52k under bulb. 20cm to right 30k. 20cm to front 27k.lamp was on only 5 mins. so reading could increase. Tank two 59k under bulb. 20cm to right 35k. 20cm to front 32k. i Averaged some of the readings as 3 units where reading diffrently With 250w se lumenarc copies. narva bulb Tank3 59k underbulb.20cm to right 44k. 20cm to front 40k 400w grotech lighting unit with reeflux 12k bulbs tank4 72k under bulb.20cm to right 52k.20cm to front 46k t5 tank with 8 54w t5s 20cm below bulbs 40K average. I even test a 150w 10k and found it was brighter than some 400w units. The lumenarc copies do give what appears a better spread; however they don’t increase the light. As I have been saying after seeing so many tanks people should think again about the fad of 400w being much brighter. In many cases it comes down to bulb choice and ballast as it can make a big difference. Water clarity is also a major factor. In terms of par .from what I read 400w does seem to give out more par than lower wattage bulbs. The sun today was about 90k lux under cloud. I really doubt any lighting is as bright as the sun as once it hits the water the metal halides will have significant drop off compared to the sun The lux meter was a cheap $55 , so the readings are not 100%, but gives a good indication. In testing I also found that 3 identical units gave different readings Quote Link to comment Share on other sites More sharing options...
chimera Posted September 5, 2006 Author Report Share Posted September 5, 2006 The lumenarc copies do give what appears a better spread; however they don’t increase the light no I doubt that they would, I can't recall a power plug hooked up to the reflector will test mine tonight using same parameters as yours. have the same lux meter. interesting to see readings. also have to make a note that my bulbs are about 4 months old now. Quote Link to comment Share on other sites More sharing options...
puttputt Posted September 5, 2006 Report Share Posted September 5, 2006 be interested in your results Chimera, find some of reefs ones hard to believe, particularly between tank 1 and tank 3 - every thing the same except wattage, same reflectors same bulb manufacturer, se etc, and the light is the same directly under but the 250w is much brighter to the side - Rubbish. I ran 250w arcadias and I know how much brighter the 400w are. You also stated that the "FAD" of 400w lights will result in less growth in an earlier thread Reef, certainly proved that wrong in my tank. As I've said before, its funny how its a FAD if you dont supply it. Mind you, owning a Deltec is apparently a FAD or "club" so i guess it works both ways. Quote Link to comment Share on other sites More sharing options...
jetskisteve Posted September 5, 2006 Report Share Posted September 5, 2006 also the tank with the 400 & the 250= the 400 was S/H so hard to call that fair, james is going to test mine this week too Quote Link to comment Share on other sites More sharing options...
puttputt Posted September 5, 2006 Report Share Posted September 5, 2006 Chimera, (whos this james chap ), Mine are 23cm from bottom of bulb to water surface, or 18cm from bottom of reflector to water surface. Quote Link to comment Share on other sites More sharing options...
reef Posted September 5, 2006 Report Share Posted September 5, 2006 find some of reefs ones hard to believe, particularly between tank 1 and tank 3 Thats what the reading was, so you are saying i made it up? There can be be differance in readings as you drop the lux meter by 1cm and the reading change a lot. i have to roughly average them out, This was just a quick reading and not scientific. also we are only reading lux so par and cri could make big differance with higher wattage bulbs. also even looking at the 250w bulb it looked brighter than the 400w and lots whiter. with the 400 & the 250= the 400 was S/H so hard to call that fair I thought that would be obviuos that the age of the bulb would make a differance and i also stated that the halide was on only for 5 mins. jsut to be fair. DH 400w lights will result in less growth in an earlier thread Reef i quess you could show me the thread.? FAD if you dont supply it. really? i actually do supply 400w lights so how dont i supply it? Also noticed that the reflector material used on the lumarc copies are not that reflective so I would assume that you could be losing about 10% light compared to an original lumenarc. As mentioned the results are only a guide as the meter is cheap and changes so much when you move it by 1 cm. it is also rated up to 50k lux so anything higher could not be that accurate. to get a better reading put a board on the tank and them taking readings would be far more accurate as all readings can then be made at exactly 20cm The tank with 3x 400w all had 14k bulbs , but one of them was so much brighter than the other two. the reading was far higher than the other two. Actually on my tank i got up to 80k on one bulb but average it out as even though you have the same bulb ballast the lux can vary. Quote Link to comment Share on other sites More sharing options...
reef Posted September 5, 2006 Report Share Posted September 5, 2006 just did another test on my tank. what a differance it makes where you put the meter. i found i had to move it all along the centre to find the best spot. reading varied from 65k to 71k by moving the meter 2cm. Quote Link to comment Share on other sites More sharing options...
jetskisteve Posted September 5, 2006 Report Share Posted September 5, 2006 youre welcome to come and measure mine or nicks DH Quote Link to comment Share on other sites More sharing options...
reef Posted September 5, 2006 Report Share Posted September 5, 2006 why would i go and test second rate tanks i always go to the best first. Quote Link to comment Share on other sites More sharing options...
jetskisteve Posted September 5, 2006 Report Share Posted September 5, 2006 in that case you need to test Pies, then putt putts then crackers Quote Link to comment Share on other sites More sharing options...
chimera Posted September 5, 2006 Author Report Share Posted September 5, 2006 hey, what about mine :lol: Mine are 23cm from bottom of bulb to water surface, or 18cm from bottom of reflector to water surface thanks puttputt. just checked mine they're 22cm from the bottom of the bulb to the water surface so not too far off at all. will test lux meter soon and post results Quote Link to comment Share on other sites More sharing options...
puttputt Posted September 5, 2006 Report Share Posted September 5, 2006 Yes I could find the thread Reef, a couple actually, heres one that wasn't even on the thread I was thinking about The narva 14k look very nice but not good for coral growth. you also told me that personally on a visit to your place, just after I got the lights. Quote Link to comment Share on other sites More sharing options...
reef Posted September 5, 2006 Report Share Posted September 5, 2006 Yes I could find the thread Reef, a couple actually, heres one that wasn't even on the thread I was thinking about Quote: The narva 14k look very nice but not good for coral growth. you also told me that personally on a visit to your place, just after I got the lights. Like i said find the post . what you posted does not say that you will get less growth compared with arcadia. it was comparing with 400w bulbs i was using. get it right before you go off . I think i would have way more knowledge on bulbs as i have actually used many. i am not a 1 yr novice reef keeper. Quote Link to comment Share on other sites More sharing options...
jetskisteve Posted September 5, 2006 Report Share Posted September 5, 2006 how long 5 or 6 yrs :roll: Quote Link to comment Share on other sites More sharing options...
puttputt Posted September 5, 2006 Report Share Posted September 5, 2006 heres another one comparing them to my old arcadias You should get a big spread of light with the big reflectors. Corals to tend to look better with a bit of blue, however whilst the arcadia bulbs are more white you do tend to get better growth but the corals look more washed out, The narva 14k bulbs are really weak so you dont get great growth, they tend to have a low par rating. so there is always a trade off between looks and growth. Quote Link to comment Share on other sites More sharing options...
chimera Posted September 5, 2006 Author Report Share Posted September 5, 2006 test results, readings also taken 20cm from bulb (and a scorched hand ) the narva is 14k, the xm is 20k directly under bulb narva, 78k xm, 80k 20cm right of centre narva, 33k xm, 35k 20cm front of centre narva, 27k xm, 28k margin of error estimated around 3,000, need a steady hand and have to average out several readings. another point to make is the XM bulb is 2 months newer than the narva's, so in all honesty i see little difference between the two brands. additionally, if you angle the sensor ever so slightly towards the bulb, it can obviously increase. in fact, holding it on the outside of the reflector, between holding it level and a 45 degree angle, the lux increased by 15k. the readings i took were with it level. seems any conclusion taken from some of reef's readings are debatable, perhaps due to older bulbs or not taking the readings when all bulbs are on for the same period of time. Quote Link to comment Share on other sites More sharing options...
Drifty Posted September 5, 2006 Report Share Posted September 5, 2006 go the t5's, 35-40 on 80 % of my water surface. I am running 5 80w. 2 6500k white and 3 blue. Readings directly under the whites are between 65 -72, and the blues 40-45 Quote Link to comment Share on other sites More sharing options...
reef Posted September 5, 2006 Report Share Posted September 5, 2006 some of reef's readings are debatable The only readings debatable are the centre readings, the sides are not far off. since the meter is designed to go to 50K lux , i would say reading over 50K are very inacurate as i was saying so that could explain why the side readings similiar as the reading is not over 50K lux. the t5s do give a far better average in lighting over the whole tank by the looks of it. 20cm right of centre narva, 33k xm, 35k 20cm front of centre narva, 27k xm, 28k Really interesting that bigger seem not to give a better spread of light as my lights read 20cm to right 38k.20cm to front 33k (test with a board so that can get a level reading. my reflectors are small and put out the same spread as a bigger reflector. Quote Link to comment Share on other sites More sharing options...
wasp Posted September 5, 2006 Report Share Posted September 5, 2006 I'm going to climb in here but please no My tank was one that Reef checked, very interesting, plus a bit weird. It has now 2 luminarcs, one with a 250 watt Narva 14 k, and one with a 400 watt Narva 14 k. Strange as it may seem, the lux meter tested higher on the 250 watt, than the 400 watt. I saw this with my own eyes. The 400 watt bulb is second hand around 3 months old against the 250 watt only a couple of weeks old, so that may have something to do with it. I have discussed this with Steve and we are going to try some more things and run some more tests. One I am hoping to do is test again in a few months to see how they are holding up. If over the bulb life the 250 continues to outperform the 400 there would obviously be no point having a 400. Could also be just the particular bulb, as Reef did find some variation among the 3 others he tested on one of the other tanks. Anyway, an educational day for me, be interesting to see what happens over the next few months. I'll report back, long as that won't tread on any vendors toes. Quote Link to comment Share on other sites More sharing options...
reef Posted September 5, 2006 Report Share Posted September 5, 2006 Thanks for clarifying that wasp. Will look to get more accurate tests when I get a grid made up so that measurements are taken at exactly 20cm and the meter is flat on a board so that the meter does not jump around when you move. Well see if I can test all my bulbs today as they all run on the same ballast and have the same bulbs/age to see the variations in readings between bulbs. Might also do some tests at 25cm as the meter might be more accurate as the lux will be below 50k which is within the meters range. Strange as it may seem, the lux meter tested higher on the 250 watt, than the 400 watt. I saw this with my own eyes. The 400 watt bulb is second hand around 3 months old against the 250 watt only a couple of weeks old, so that may have something to do with it Another big factor is that the 400w was only on for 5 mins. Quote Link to comment Share on other sites More sharing options...
Jeroen Posted September 5, 2006 Report Share Posted September 5, 2006 Hi, Just wondering if the meters tell you at what wavelength they are calibrated. Do they measure the intensity of light at 6500 Kelvin (or maybe even lower) or 14000 Kelvin. Can you adjust this? That would be interesting then you can check which part of the light spectrum fades quicker whne the light ages. Jeroen. Quote Link to comment Share on other sites More sharing options...
Ira Posted September 5, 2006 Report Share Posted September 5, 2006 If it's a lux meter then your question isn't really relevant. They don't read a certain frequency or kelvin. It's a reading of the entire visible spectrum weighted to match the frequency response of the human eye. Quote Link to comment Share on other sites More sharing options...
reef Posted September 5, 2006 Report Share Posted September 5, 2006 Hi, Just wondering if the meters tell you at what wavelength they are calibrated. Do they measure the intensity of light at 6500 Kelvin (or maybe even lower) or 14000 Kelvin. Can you adjust this? That would be interesting then you can check which part of the light spectrum fades quicker whne the light ages. the meter only test for lux Started a new thread. http://www.fnzas.org.nz/fishroom/here-vp170672.html#170672 Quote Link to comment Share on other sites More sharing options...
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