T8 Or T5 Electronic Or Magnetic Ballast/starter

[UNV_Rasta]

Alot of forums seem to think that the only differeence between aquarium tubes and standard T5 tubes is the word aquarium written down the tube and the 200% markup is this correct ?

Yup

 

[JoshuaA]

Interesting point here, do reflectors make a significant difference at all?

I only have 2 x 18w T8 Arcadia Original lamps and two reflectors and I can maybe gauge a 25% difference in brightness at best. Is it anywhere near that, it clearly isn't the 100% bonus they boast about.

Reflectors make a huge difference in the output of light from your lamps, also keeping them clean (reflectors and lamps) makes a huge difference too.

SD.

Interesting, how much of the light do you think is reflected back in the tank? I do notice I can actually open the lid without being blinded of course which is a bonus!

What's the best method of cleaning a tube, just a dry dusting cloth?

I will try to keep this simple, if i go all technotalk you have permission to slap me.

Well a glass mirrored reflector should reflect nearly 100% of the light energy, just think of your bedroom mirror, the reflection is not darker than the real thing is it? Unfortunatly we cant very well use a curved glass mirror as a reflector because it would be too expensive. So we use curved "mirrored" plastic or metal.
This is a very good reflector as well & will bounce back about 50% to 60% of the light that hits it
The thing about your aquarium lamp is that half of its light output goes up toward the hood rather than down into the tank (I am oversimplifeing here). So if we can make use of this "lost light" we can effectivly nearly add half again the light output of the lamp.

Lets say that we pick a spot inside the aquarium & measure the brightness with a lux meter. Without a reflector it is 100 lux but with one it would be more like 150+lux that is a big improvement.

I hope this helps.

I'm more concerned about the actual coating isn't as reflective as they make out to be. I'm some what unimpressed, inevitably there will be some wastage however it does seem like its very poor advertising as if they claim "Boost your lighting by 100%" it would mean that I pumping 36w per bulb into the tank rather than the 18w each I have.

The intensity of light with and without clearly isn't 100% it really does appear to be more along the lines of 20/30% area.

Also it isn't the glass itself that makes it more reflective its the higher quality Silver coating, where as our plastic lamp reflectors use the natural metals reflectivity.

 

[waterdrop]

It's a tricky topic, trying to talk about light and light measurements.

Light is a type of radiation. It often needs to be talked about differently in scientific labs than it is in applied situation like home lighting and other areas of practical areas.

In the situations we discuss we are nearly always talking about a broad spectrum of light, many different frequencies all radiating out together from a source (as opposed to a laser, for instance.) The light intensity measurements we hear discussed a lot are lumens and lux, which most casual observers tend to think of as simple quantities of "amounts of light pouring off a lamp and illuminating something." Both of these quantifiers however are actually numbers that have had weights applied to all their frequencies based on an "average" human eye. They are "photometric" quantities, whereas, without the "human eye filter" applied, for the same sample of light, there would be a different "radiometric" set of numbers for each frequency of light. Lumens is a number attempting to represent all the light going out in all directions but with the human filter. Lux is a number attempting to represent the light actually arriving at a given spot area, also with the human filter.

So in most human applied needs, lux tells you more about the practical, useful light on your subject than lumens does (making lumnens sometimes more useful to marketers who need to find ways to make it a little more difficult for you to compare their products directly, lol.) But plants don't have eyes! The plant leaf is a little biochemical factory that is very much working with the "radiometric" numbers (that we would use to measure photons coming in,) not the "photometric" numbers we humans use because of our eyes. Does that make sense? The leaf tissues of a given species have some frequency absorption curve (in a very general sense we can say that blues and reds get used more by plants and obviously greens get bounced back at us) and a set of radiometric numbers would be what scientists would work with in a botany lighting lab, I believe.

OK, back to US! Does ANY of this matter to us much? Well, maybe a little sometimes but NOT MUCH, I would suggest. It only really serves to hightlight our general inability in practical situations to apply any numbers that have real meaning to the situation. In truth, we are terrible at really knowing how many and what frequency photos are coming off our lighting systems and actually hitting a given leaf and we are terrible at understanding what any given leaf of any given species would really need to contribute correctly to the well-being of the plant! But of course we know the NEED light and we know rather a lot of practical things about getting light to them. The -great- thing about that is that it should free us realize that we are back to simply observing our tank. We use various crude shared info to hopefully get ourselves in the right range of things and then we observe the quality of our plant growth and the algae situation. Does my white plastic light strip reflector from PetSmart absorb a lot of photons rather than reflect them? Of course it does, but (disregarding my electric bill for the moment) does it hurt my Anubia or help it? I probably can't know, without longer observations, because I don't really have a lot of real knowledge about whether that Anubia would have been happy way back in a deeply shaded creek or perhaps at the edge of a hot sunny stretch of creek. And that's not even to mention the seasons and the plant's ability to have dormancy mechanisms based on day length or moisture or other things!

I feel we kind of get kind of left free to experiment and try things, because the plants have a very wide range of what is *sufficient* for growth and because science and engineering don't really give us a whole lot of easily applicable tools that would make a whole lot of difference beyond our own simple observation and experimentation.

(sorry guys, I know that was off-topic more or less, it's just where my mind was wandering and I thought it might be interesting to a couple of you out there... )

~~waterdrop~~

 

[JoshuaA]

Interesting read there WD.

What I mean by the reflected light is pretty much "Dim" and "Not so dim". It's a measurement we can all make with our eyes and come to a conclusion. Of course if I was to have the reflector then and not there we can compare them.

For more reading WD you should look into explaining excitation, electrons and energy levels for how these lamps work, it is actually rather interesting with some background knowledge it can help explain a lot of things for every day life.

Slightly off topic, I have a 250mW laser pen which is just mind boggling when you imagine the low amount of energy actually in it compared to anything else, this pen can pop balloons from the other side of the room and etch onto black plastics. I have actually played with it experimenting with my reflectors on my tank and directing my pen at the reflector back at a black surface does not resulting any burning or smoke. Of course directly does and this is a matter of cm's away.

 

[Aqua Tom]

Whoaaaa, ok we seem to be going a bit technobabble here.


Reflectors mean more light. simples