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I just checked the PAR output of an Arcadia Series 3 against the AquaMedic Aquastarlight future and was amazed at the difference. Both are clean and have fresh 50000k 150w bulbs in them.
At 7" (air) from the arcadia unit the PAR measured 380.
At 7" from the ASL future, the PAR measured 850. That's massive difference!
Has anyone else tested their units or reflectors? Please post.
I also noticed that the PAR output of an 11month old 50000k bulb is only 2% lower than that of a new bulb.
good info that, suppose it makes sense as to why aqua medics are more expensive then as they are 2 times better almost :lol:
Interesting ! :)
You may want to measure (and perhaps you did ? ) the PAR at several points - eg directly below the lamp and then along the edge of a 30 cm diameter circle centred on this point. That'll give you an idea of the total performance. Different reflectors will have different distributions. It's possible for a very poor reflector to produce one or more "hot spots", whereas a good one will give a more even output across the desired area.
Fwiw, 45 cm below 10,000K BLVs I get 750 PAR per 150W lamp (400W BLVs but I adjusted the result).
I would guess that lamp type (brand, kelvin) makes a big difference too. You are lucky to be able to eliminate this in your test.
kim
(ps clean glass ? :unsure: )
simon garratt
19-10-05, 17:45
PS.....no glass....... :D
Hi Kim - Sorry for this vague question but in your opinion, what would be the smallest par reading for keeping sps? I have read an article by Sanjay Joshi on this subject somewhere, just can't remember where...Thanks
Matt
Another potential contributor would be the different brands of ballast, which can also have a signficant effect on lamp outputs.
Keith
P.S. Dear Santa, I really, really want a PAR meter :whistling:
I am not the livestock/SPS specialist.
One very good resource in Andy Hipkiss's site, because he has some pikkies of SPS together with the PAR reading at that point (that will be much less than at the water's surface - they are farther away from the lamp, and water's surface will reflect light). I don't know any other site with these readings - few people have a PAR meter.
Guru (http://www.andy-hipkiss.co.uk/)
Look under "Pictures".
You can also consider natural conditions. Peak (ie lunchtime) intensity at the water's surface on a tropical reef is about 2,000 PAR. Converted to Lux (which is what most lightmeters read) that's about 120,000 - the conversion is only valid for natural daylight btw, don't even consider using it for a 14,000K halide ! :wacko:
These lighting levels would need about 1,000 watts of lamp per square meter area of tank.
But many people get away with plenty less. There's much witchcraft in colour of lamp, plus of course different species have different tolerances, and different specimens come from different depths. Best to see tanks you like, and find out what they've got. Once you start to think of colouration, there's also nutrient levels and simple differences between specimens to consider.
kim
Hello. I'm just about to try my 250w Aquabay ballast with a 10k BLV, no glass. The 150w bulbs were double ended, so they have to have glass, and the glass was cleaned spotless before I tested. Actualy, I did test withthe glass covered in salt spots and was surprised again that it only removed at most 5% of the PAR.
Kim, how did you calculate that PAR reading? Are you testing a 400w bulb with no glass? As far as I know 150w DE bulbs must have glass to protect from UV. So comparing the singles against double ended bulbs is probably not a good idea. Although, in the long run I suppose it probably just shows that single ended bulbs are great!
PAR from 10k BLV 250w in an Aquabay box, 6" from bulb = 1200ish.
:thumbsup:
Andy, Have you tried the Venture 4k lamp
I measured the PAR (Apogee Quantum Meter). The conversion to Lux (lumens/m2) is the standard one used for natural light.
Yes, I haven't a cover glass, but I reckon that it's a fair comparison of lamps used according to their instructions. Of course, SE lamps have an extra glass envelope built into them, which is why an extra sheet isn't needed.
I am not sure that SE lamps are great, but there is a lot of funny stuff spoken about the higher efficiency of DE versus SE lamps and many people say that SE are rubbish, which is simply not true. Both types pretty much emit the same amount of energy, according the makers (I've spent hours trawling the makers' websites to satisfy myself of this) given the same power supply.
And let's face it, if that weren't the case, industrial users who may have hundreds of the lamps and huge electricity costs would switch to the better version. B)
But I think that it's easier to build a good DE refletor for our purposes - we usually want to confine the light spread.
Most SE reflectors are also designed to spread light in a wide area (which is why I modified mine). It's about 30 cm top to bottom, which lots of people wouldn't like.
When the 400W DE lamps are more easily available in a range of colours, I think that SE will be redundant for our purposes except for the largest of tanks. Though I still think that the "low profile" reflectors we have in "designer label" aquarium lights are too shallow. If they were deeper, we could hang the light 30 - 45 cm above the water with the same effect. I designed my relector for this sort of height.
kim
Hi Adam, no I haven't.
Kim, the single ended bulbs obviously only have less than 1mm of glass as protection, whereas the double ended bulbs are protected by 4-6mm of glass. I would assume that the thicker the glass, the more radiation it removes?!
All good fun. I'm going to do some T5s next. They're a bloody mystery too.
Oh, almost forgot. The reason Aquamedic Percula tanks are now supplied with ocean lights and not aqua starlights is cost. And the cost of the Aquastarlight is apparently all in the reflector (according to Aqua medic). The retail price on a starlight is up around £550, the oceanlight roughly £320 I believe. Big difference. I'd like to test an oceanlight, but don't have one to hand.
:lol:
I'd love to see a reflector that costs that much ! Some design costs (not much, we don't need a piece of lab equipment), maybe they even coat it in silver (will only add about another 5 % light)....
I'm in the wrong business.
Yes, thicker glass will remove more UV - how much depends on the glass, of course.
Good luck with the fluorescents. Clayton did a little work on this once. Fluorescent reflectors....grrrrh. Trouble is, if you pack a lot of T5 tubes into a small space they do tend to make it difficult to do much more then put an inverted baking tray over the lot.
:)
kim
lol kim :D how about a silver coated baking tray?
mark_dimeck
23-10-05, 07:13
Interesting - thanks popsok
This goes some way to help explain why I was convinced I had better SPS growth / colour under my previous system which used a twin 150W ASL Future.
Using a triple 150W Series 3 on my current system.
Must say I was impressed with the build quality of the Aqua Medic unit.
And I was thinking it was in the bulbs! Have now changed mine from Arcadias to an Iwasaki 50kk and 2 BLV 10kk's - which does seem an improvement.
Looks like I gone as far as I can with the Series 3. Will probably supplement with some T5s once I work out how to integrate them neatly.
Mark
After looking at that one arcadia and aquamedic unit, I'd love to get my hands on more types to test. I expect the cheaper aquamedic 'oceanlight' would be similar in performance to the series 3. I've never liked Arcadia's bulbs or T5s anyway (colour preference), and I found that if you put a 14kk arcadia bulb next to the 50kk iwasaki, the arcadia bulb just looks stupid. Ramble, ramble, ramble...
Simply send your metal halide units to the address below :D
What address? ;)
I'd love to know how the arcadia series 1 stacks up against the 3 and weather they have compromised performance for style.
BTW you can easily get 2000 PAR atyour tank's surface. You just need to lower your 150w unit to 1 inch from the surface. :lol:
I wonder if its possible to get sheets of Quartz? They use quart to make UV sleeves presumably because it removes less energy from the tube within. I wonder if Quartz cover glasses (cover quartzes?) could be viable? I wonder then if it wouldbe possible to lower say a 250w halide 2-3 inches from the surface? Presumably the only downside then would be heat?
I must stop thinking, its making my head hurt.
Andy
The reason for a quartz sleeve as opposed to glass on a uv sterilizer is because quartz doesn’t block uv so a cover quartz on a double ended halide would be pointless and dangerous.
You can run a halide 2” from the water but as you said heat would be a problem plus if you use a reflector designed to be 8-12” from the surface the light would have a narrower spread so you would need more of them to cover your tank.
If you want a brighter tank you could just use a 400w instead of a 250w :thumbsup:
PS. It's probably best not to post suggestions when your head hurts :P
Ad, I was talking about single ended halides, but you knew that didn't you.
Originally posted by popsock@Nov 1 2005, 00:23
Ad, I was talking about single ended halides, but you knew that didn't you.
No I’m sorry I assumed that because you were talking about replacing cover glasses you must have meant double ended. If you meant single ended then there is no need to replace the glass just remove it. Either way what difference do you think that the cover glass makes to the minimum distance between the halide and water?
A single PAR figure taken directly below a reflector is a fairly useless piece of information WRT to the effectiveness of a particular reflector, but okay for comparing lamps. Afterall it would be easy to make a reflector that made an intense hotspot of light, the skill is to make one that spreads the light evenly over an optimum area.
To test that requiresmeasurements taken from hundreds of points below a reflector. This is what Sanjay has done with his 3d plots in one of his articles.
Danny are you talking from experience or theory? So far I've only seen a linear reduction in PAR the further from the centre of the lamp I go, in any direction. No hot spots. I've only tested the series 3, the arcadia ASF and a generic aquabay.
Adam, the point I was making was that maybe its possible emulate true reef lighting, if there was some way of getting the halides low over the water without them blowing up from splashing water. Whilst its true that you could just use massive wattage lamps, that's expensive and wasteful, but in the end maybe the only way to do it.
One interesting thing I have noticed is with the adddition of the 250W 10K BLV to my tank..
My mushrooms have all reduced in diameter hugely and show no sign of incresing again until I put them in the shade, obviously they don't need so much light, so what sort of depth would you find LPS and shrooms and other low light corals sitting at in the wild?
With the huge light intensity penetrating the water they surely must be found at much greater depths than SPS. I'd love to find some shrooms or lps that DO need a high light output as I can provide the lighting easily.
Originally posted by popsock@Nov 1 2005, 10:17
Danny are you talking from experience or theory? So far I've only seen a linear reduction in PAR the further from the centre of the lamp I go, in any direction. No hot spots. I've only tested the series 3, the arcadia ASF and a generic aquabay.
I expect Danny is refering to the research carried out Sanjay.
He published a series of articles in Advance Aquarist:
Article 1 (http://www.advancedaquarist.com/issues/mar2003/feature.htm)
Article 2 (http://www.advancedaquarist.com/issues/july2003/feature.htm)
Article 3 (http://www.advancedaquarist.com/issues/mar2004/feature.htm)
You'll see why Kim is a fan of Diamondlite reflectors....
Keith
Beat me to it Keith :thumbsup:
But it is just common sense really, the wider the spread of light from a reflector then the lower the intensity will be in a single point. Whereas in you produce a more focused beam then it will have greater intensity but not necessarilty more suitable for a tank.
Some reflectors Sanjay tested appeared to have more than one hotspot.
I think that there are two elements to the reflector, addressing three points:-
First, the shape of the reflector should be such that the "spread" of reflected light is sufficient to illuminate the chosen section the tank and no other, eliminating waste (point 1), and do so evenly (point 2).
Second, the reflector needs to be sufficiently deep so that the light emitted directly from the lamp itself (ie without reflection) is also limited to the same section of tank, also eliminating waste (point 3). (By the nature of most lamps, this light will be evenly spread.)
This is my problem with shallow (ie "slimline") reflectors, and is why the much deeper Lumenarcs do a good job. The difficulty with big lamps (such as SE lamps) is that it's tough to limit the spread of direct light because the reflector is already pretty large to accomodate the lamp. In fact, the best solution seems to be to dramatically shorten the reflector and allow the socket end of the lamp to stick out the back (it can no longer fit inside). Very very little light is lost this way, I found.
On the heat, one day I want to play with the specialised white paints you can buy which reflect very well in the visible spectrum (almost as well as aluminium, they claim) and are transparent in the infra red. So you don't reflect heat into the tank. Some horticulturalists use these. My problem is what do you paint them on ? And how long does the paint last given all the UV ?
If it's an aluminium base, the aluminium will still reflect the heat back down as before :wacko: (aluminium is sadly a superb reflector of infra red).
kim
Glenn@home
01-11-05, 20:09
the distance of the lamp/reflector from the water wont make that much difference in terms of tank water temp assuming that the water is moving.
Since youre talking about heat, the rise in temp of the water is about joules in versus mass of water.
rise in temp will be 4200 joules per degC per gramme or something like that, cant remeber the specific heat capacity of water for certain and cant be bothered to check it.
If you want to try to introduce time then a watt is a joule per second......well whatever, the only reason distance will make a difference is if you loose energy outside of the tank or the water isnt moving in whihc case you will see a larger increase in temp of water locally as against a smaller rise over the whole tank.
HTH
Glenn
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