waterproof LED

[95accord]

i was wondering if there was a good brand LED light out there that would be placed in the sand bed of a aquarium? a walmart brand or something.....ive seen cool set-ups for moon lighting that are spotlights that shine down...but i wanted to be different and have lights shinning upwards lol
anything out there that would work for this application?
i know LEDs wont heat up the water since they are cool to the touch.

 

[BeanAnimal]

Actually if you put 20W worth of LEDs into the water then they would put the same amount of heat into the water as a 20W heater

Anyway...

You would have to waterproof an OEM LED fixture or build your own. You can seal the electrical connections with heatshrink that is designed for underwater use or use epoxy or silicone. You will also have a problem keeping the LEDs clean.

Have fun

 

[95accord]

<a href=showthread.php?s=&postid=10942771#post10942771 target=_blank>Originally posted</a> by BeanAnimal
Actually if you put 20W worth of LEDs into the water then they would put the same amount of heat into the water as a 20W heater

never thought that.....kinda obvious tho when you think about it lol...hmm...might be something worth considering....

 

[NeveSSL]

<a href=showthread.php?s=&postid=10942771#post10942771 target=_blank>Originally posted</a> by BeanAnimal
Actually if you put 20W worth of LEDs into the water then they would put the same amount of heat into the water as a 20W heater

How so? 20w of lights doesn't mean 20w of heat... it all depends on how efficient they are... and I think most LEDs are quite efficient considering they don't put out much heat.

Let us know if you figure something out 95accord! I can't think of anything right off the top of my head... I would think corrosion would be the (obvious) biggest factor.

Brandon

 

[BeanAnimal]

You ask how so?

1) LEDs do produce a significant amount of heat. Most of it is conducted through the LED die or electrodes, not radiated from the light producing side.

2) LEDs are NOT that efficient in terms of creating light from energy. They lag behind MH and Fluorescent technologies. The OP is likely talking about standard 5mm LEDs which are not at all efficient.

3) Watts are Watts. By the very definition, we can measure the power consumption of ANY device and determine how much heat it produces.

By definition we can take 4 identical insulated boxes:

Box 1 20W worth of LEDs
Box 2 20W resistive heater
Box 3 20W fan
Box 4 20W speaker

All 4 boxes will reach the same peak temperature in the same timespan. We can of course argue that the boxes with the speaker and fan will "leak" some energy due to vibrations (sounds) making their way out of the box. However this loss is very minimal.

In the case of the speaker MOST of the energy is released in the form of heat produced by friction and magnetism. Much of the resulting sound heats the box components and very little energy leaves the box.

If we used clear insulated boxes you would find that the light energy that leaves the box is also not very significant and in fact most of the 20W turns to heat in the box. The less translucent the box the less energy escapes. We need very strong lights to penetrate deep tanks for the same reason.


This is basic physics but eludes most people

 

[coolfish5]

I would think one of the hydor LED's would work fine for this. I know its not DIY but they are simple and fairly inexpensive.

http://www.drsfostersmith.com/produ...&Ntx=mode+matchallpartial&Np=1&pc=1&N=0&Nty=1

I have one I put in a freshwater tank that I picked up at the LFS. It has been working fine for a while, though the suction cup falls off sometimes as they all seem to over time.

Just a thought

 

[BeanAnimal]

Yup that looks like it will work

 

[NeveSSL]

Thanks for the reply bean. I'll PM ya... don't want to litter this thread.

Brandon

 

[daven]

Marine aquariums...the final frontier. These are the voyages of the Spaceship Bean. It's five year mission: to explore strange new worlds, to seek out new life and new civilizations- to boldly teach people the basics of physics and thermodynamics.

lol. I always love this, oft repeating, conversation. Usually turns into a major back and forth.

Of course Bean is correct.

 

[kgolem]

<a href=showthread.php?s=&postid=10946855#post10946855 target=_blank>Originally posted</a> by BeanAnimal
You ask how so?

1) LEDs do produce a significant amount of heat. Most of it is conducted through the LED die or electrodes, not radiated from the light producing side.

2) LEDs are NOT that efficient in terms of creating light from energy. They lag behind MH and Fluorescent technologies. The OP is likely talking about standard 5mm LEDs which are not at all efficient.

3) Watts are Watts. By the very definition, we can measure the power consumption of ANY device and determine how much heat it produces.

By definition we can take 4 identical insulated boxes:

Box 1 20W worth of LEDs
Box 2 20W resistive heater
Box 3 20W fan
Box 4 20W speaker

All 4 boxes will reach the same peak temperature in the same timespan. We can of course argue that the boxes with the speaker and fan will "leak" some energy due to vibrations (sounds) making their way out of the box. However this loss is very minimal.

In the case of the speaker MOST of the energy is released in the form of heat produced by friction and magnetism. Much of the resulting sound heats the box components and very little energy leaves the box.

If we used clear insulated boxes you would find that the light energy that leaves the box is also not very significant and in fact most of the 20W turns to heat in the box. The less translucent the box the less energy escapes. We need very strong lights to penetrate deep tanks for the same reason.


This is basic physics but eludes most people

LED's are not as efficient as most people think, especially in applications where the device is designed to approximate broad spectrum emmission, but in instances where a single wavelength of light energy is required, LED's are much, much more efficient than other types of conventional household lighting systems.

Basic physics says that energy cannot be created or destroyed, only changed to a different form, this is the law of conservation of energy.

Of the four devices mentioned, all change electrical energy into other forms.

All produce heat energy, and all (except the speaker) are typically rated at the energy consumed to function under normal electrical conditions. Speakers are typically rated at either constant or peak power levels that can be applied to them safely.

So in the cases of the heater, the fan and the LED's to ignore all the energy except that which is transformed into heat is incorrect. I can safely put an unprotected hand on a 1/2 horsepower (372.85 Watts) moter running under load, but touching a 20 Watt resistive heater will result in burnt flesh.

There is a heat energy by-product, that is a residual amount that is the total power consumed minus the product of the efficiency calculation for the device.

The speaker cannot even be considered here. 100 watt speaker systems don't need cooling fans, and operate much cooler than a 100 watt incandescent lamp, for example.

 

[BeanAnimal]

Kgolem, thanks for taking this on a tangent

We are not talking about the ratings of the speaker. We are talking about a speaker that has its coil being driven at a constant 20W. Therefore, there is NO difference. That is WHY we can measure WATTS and make meaningful comparisons.

Grab the shaft of that motor and see what the friction does to your flesh

The efficiency of the device has no bearing on the basic premise here. Yes, LIGHT can escape the room. Yes, SOUND can escape the room (box, tank, whatever). Yes Corals can STORE energy by chemical conversion ENERGY provided by LIGHT.

The point is that an submerged LED being driven at 20W, a submerged fan (a pump) being driven at 20W, a submerged speaker being driven at 20W will each impart the same amount of ENERGY into the tank as a 20W heater. MOST of that energy will become HEAT stored in the tanks mass. Therefore each device will heat the water in a similar fashion.

We can nit pik the differences:

The LED will leak some light out of the tank and will allow the corals to convert some of the light into chemical energy and store it as biomass.

The speaker will leak some energy from the tank in the form of sound.

The fan (pump) will leak some energy from the tank in the form of sound also.

 

[kgolem]

Without furthering the conversation in any general direction...

By definition we can take 4 identical insulated boxes:

Box 1 20W worth of LEDs
Box 2 20W resistive heater
Box 3 20W fan
Box 4 20W speaker

All 4 boxes will reach the same peak temperature in the same timespan.

I disagree with your assumptions here, you obviously do not, so we agree to disagree, and other users can decide for themselves.

 

[kgolem]

A 20 watt motor (1/38 HP) motor, one might be able to grab the shaft and stop it without damage to the hand. Depending on how efficient the motor is.

 

[kgolem]

Moderator; my apologies for the double post, please delete the first the first of the pair.

Edit, I was able to edit the posts so they now make sense. Again; I am sorry for the extra bandwidth occupied here.

 

[BeanAnimal]

<a href=showthread.php?s=&postid=10949122#post10949122 target=_blank>Originally posted</a> by kgolem
Without furthering the conversation in any general direction...



I disagree with your assumptions here, you obviously do not, so we agree to disagree, and other users can decide for themselves.

I have not assumed anything. That is the problem. You disagree with the basic physics and call it assumption?

Please consult the definition of WATTS. Then please note that the devices in question are consuming the SAME amount of ENERGY. They (the devices) ARE NOT storing, destroying or creating energy. They are therefore only transforming energy. We can trap that energy and measure it. It will, by definition and by physical law, be exactly what was put into the device.


The very definition of a WATT allows us to make these statements.

Again, the ONLY energy that can escape from our experiment is via sound waves, light, magnetism. It can be shown that the energy in any of those cases is minimal.

So no we do not just agree to disagree. One of us is arguing science, the other opinion based on a gap in understanding.

Please do yourself a favor. Build three small insulated boxes (say 1 cubic foot).

Put a 60W lightbulb in 1 of them and a 60W resistor in another and a 60W motor in the third.

You will find that all 3 boxes reach the same constant temperature at the same rate. This is a grade school science experiment, not advanced physics. We can not have a meaningful conversation about this subject until you understand that basic experiment and the definition of ENERGY and what exactly a WATT (or any unit of POWER) is and what it means.

The advanced physics would be discussing how each devices uses and transforms energy and how that energy then becomes heat. We can certainly have that discussion, but not until the most basic principles here are understood.

You may want to know that insulated boxes have (and are still) used to measure the power consumption of devices, in the exact manner I have described.

1 Watt = 3.413 BTUs an hour. Therefore ANY device that consumes 20W will pump out 68.26 BTUs an hour. Nice and simple

 

[kgolem]

Please don't assume what I do and do not understand, you have no idea.

You have the last word, I think that is all you require. Other members may read and decide.

 

[BeanAnimal]

<a href=showthread.php?s=&postid=10949441#post10949441 target=_blank>Originally posted</a> by kgolem
Please don't assume what I do and do not understand, you have no idea.

You have the last word, I think that is all you require. Other members may read and decide.

Again, I have not assumed anything. Your comments on this subject have very cearly demonstrated a lack of understanding.

I will remind you that YOU responded to my comments in this thread and did so in disagreement. I have responded to those comments in an attempt to show why I am correct. I have done so with application of basic science that many of us were exposed to at a young age. We are not talking about advanced science here, just the basics.

It has nothing to do with the "last word" or "agreeing to disagree". You asserted that I was wrong and I have kindly responded with factual information.

 

[goldmaniac]

<a href=showthread.php?s=&postid=10949584#post10949584 target=_blank>Originally posted</a> by BeanAnimal
Again, I have not assumed anything. Your comments on this subject have very cearly demonstrated a lack of understanding.

I will remind you that YOU responded to my comments in this thread and did so in disagreement. I have responded to those comments in an attempt to show why I am correct. I have done so with application of basic science that many of us were exposed to at a young age. We are not talking about advanced science here, just the basics.

It has nothing to do with the "last word" or "agreeing to disagree". You asserted that I was wrong and I have kindly responded with factual information.

Bean, 20 W does not equal 20 W of heat. a 20W heater converts the majority of energy into heat, where a 20W florescent bulb turns most of that Wattage into light, not heat. a 20 watt incandescent (sp?) is much hotter than a 20 watt florescent bulb that your screw into your lamp. that's becuase of the difference in efficiency in converting energy into light without releasing heat.

I believe you basic premise is fundamentally incorrect.

WATT: Pronunciation: \ˈwät\
Function: noun
Etymology: James Watt died 1819
Date: 1882
: the absolute meter-kilogram-second unit of power equal to the work done at the rate of one joule per second or to the power produced by a current of one ampere across a potential difference of one volt : horsepower

this has nothing to do with heat. Has to do with energy.

This has prompted me to comment on your initial statement about 20w of LED light in a fishtank, that's a HUGE amount of light coming out of LEDs. the whole attraction of LED lights is the extremely small amount of energy they reqire to run.

just Google "1 watt LED" and see all that comes up. there's 1 watt LED flashlights. any moonlights would be fine with a few .1 watt LEDs, I'd imagine. I'm just guessing on what available wattage LED's are out there.

This is not a pi$$ing contest... I'm just attempting to make sure that misinformation is kept to a minimum.

G.

 

[easttn]

You girls crack me up.

95accord,

There are three basic routes to go for sealing an electronic circuit.

1. Paralyne - Absolute the best product in the world for this application. This can be put down to 5 micrometers (0.0002)in. thick and it exhibits very little absorption in the visible light region and is, therefore, transparent and colorless (no masking required). It will not leak in the lifetime of any LED if applied correctly. But thats the problem, you would need to hire a contractor to put it on unless you own a vacuum chamber and some other esoteric crap. Anywho, google Paralyne.

2. Polyurethanes - probably your best bet. UL approved and is available in aerosol spray cans. Use the Humiseal 1A33. If you really want to make sure its sealed buy a pint and dunk it in. You will need to cover the LED lens during this process and remove when complete for best light output.

3. Acrylics - readily available, typically not UL approved - but they do have aerosol cans that will protect an LED for our application. Same here with the masking. Last choice imo.

There are also epoxies and silicones, but I never used those. Silicone is probably a good option, but because of what it could do to manufacturing equipment I never utilized it.

GL, now you rocket scientist go pee on someone else's thread ;D

 

[BeanAnimal]

You say you want to keep the misinformation to a minimum.

I am not being rude, but do you even understand the definition that you posted?

You have said that this has to do with ENERGY, not HEAT. Your comments indicate that you do not understand either very well.

I suppose we can define HEAT and define ENERGY and all of the forms of ENERGY. We can talk about WORK and Joules and Horsepower, but none of that is needed.

May I remind you that 1 WATT = 3.413 BTUs per Hour. This is a constant, not something that changes or only applies sometimes.

Therefore, we can measure the HEAT given off by a device and know exactly how much power it consumes. This also means that if we know how many WATTS a device uses, we know how much heat it gives off. It is a direct relationship that is dictated by the basic laws of thermodynamics.

Furthermore your said:

This has prompted me to comment on your initial statement about 20w of LED light in a fishtank, that's a HUGE amount of light coming out of LEDs. the whole attraction of LED lights is the extremely small amount of energy they reqire to run.

That would indicate that you also do not understand LED technology very well either. If you are using "google" and anecdote to come to that conclusion then your statements are very understandable. There is no problem with that. The irony is that you have been fooled by a lot of misinformation... something you are trying to combat

LEDs are being advertised as many things that they are not. The technology is certainly improving and will soon become more efficient than other forms of lighting. That however does not (and never will) exclude it from the basic laws of thermodynamics. A 1 WATT LED will ALWAYS produce 3.413 BTUs of HEAT per HOUR.

These nice tidy "laws" allow us to accurately predict how electronic devices will work, how rockets will fly and how much fuel they will use. They help us determine how much electricity it will take to run a toaster on a 700 mile extension cord or send a radio signal to mars. We can use these known relationships to size the furnace for your house and determine how much it will cost to operate, before we ever plug it in.

Maybe this will help:

As you can see WATTS are still WATTS and everything still works out

Furthermore you can add a few columns. "HEATER" and "MOTOR" fill in the rows and still come up with 100% in the total column. Why? Watts are universal my friends. When we measure the WATTS we know the HEAT and vice versa.