# DIY moonlight



## idris (16 Mar 2021)

Having read posts by the more knowledgable forum members about the downside of split photo-periods, my 100W T5s are on for 7hrs a day. 

Until I spotted early signs of a BGA outbreak last night, I was wondering about adding a moonlight so I can watch the tank morning _and_ evening.
My current thinking is a LED strip : 12v / IP67 / 5W / 250 lumens. (If I'm feeling clever, I might get it to start white and fade to blue, and then off completely over an hour or so.)
In a 2'½' deep tank, is this likely to be enough to view the inhabitants without giving a significant boost to algae?


----------



## dcurzon (16 Mar 2021)

I think you'd be able to see them ok.  Cant answer about the algae, but you can play with brightness/duration. I had 5v strip running inside a hood at similar depth running from USB and that was ample for dim viewing.  You could fairly easily automate it with Alexa including to increase/decrease and colour change.


----------



## idris (16 Mar 2021)

Alexa? Pah!. I don't trust Amazon not to snoop on my fish watching habits. Anyway, I'm planning on doing it in C++.


----------



## dcurzon (16 Mar 2021)

Thats cool, there's plenty of ways to do it, but for most people the wifi controllers would be easier (either via manufacturer app or Alexa app on phone).  I ran one led strip twice the length of the hood (along and then back again) and that was good enough to see, and create a dawn/dusk routine


----------



## idris (16 Mar 2021)

Only joking about Alexa. I know not everyone wants to mine their own iron ore and forge their own knife before they can skin a cat.

Do you know what spec your LEDs were? From what I've seen of the USB strips, they're relatively low powered.


----------



## dcurzon (16 Mar 2021)

they were 5050's, generic Chinese rgb led strip with wifi controller, about £14 on amazon, wowled brand... have redeployed them as a backlight since


----------



## idris (16 Mar 2021)

Thanks. 30 or 60 LEDs per meter?


----------



## zozo (16 Mar 2021)

If you are going RGB strip with a decent controller able to set each channel separately. Then I would definitively steer away from Blue light and stay in the white light range... I'm not sure where the blue light to mimic moonlight came from? Is it the closest thing to give a sense of darkness?

But since when you go out at a clear full moon night there is nothing blue about the moon and light it reflects.

Anyway, try to go with more natural colors preferably towards the yellow or maybe greens or browns... At very low intensities this looks much more appealing and much more natural in the way it reflects off the plants and fish... I bet once you have tried it and seen it, then blue will look very odd after that.

Take a look at this website.

Then if you use a controller that can set the channels per percent intensity you can create any color displayed on this website pretty near the same (if you would shine the RGB light onto a white surface). Then you only need to keep dividing the percentages into equal parts down to get to the preferred intensity.

For example one of my personal favorite moonlight colors was

honeyrgb(100%, 90%, 67%)
This is full blast intensity 100% RED - 90% GREEN - 67%BLUE. Then make this 50%, 45%, and 33% it's half the intensity but still the same color. make 25%, 22%, and 16% is 1/4 the intensity and still the same color. 12%, 11%, and 8% is 1/8 the intensity but still fairly the same color. 6%, 5%, and 4%. 

If you have trouble finding a controller able to do this I can advise you to use the gold old TC420 this still uses the older version of PLED software that goes per 1 percent per channel.  With this controller, it is even possible to create a moonlight effect with clouds hovering over the night sky playing with the intensities going slightly up and down, or maybe even change the color a tad while it is changing in intensities. Or go from the Dusk till dawn from Crimson Red evening sky to the slightly Orange dawn sunlight and all in between. I'm not aware of other controllers able to do this, could be more modern ones are available. But the TC420 is the only one I did this with and even tho an oldy it does a darn good job in it.


----------



## idris (16 Mar 2021)

Thanks Zozo. _"Why blue?_" is a very good question. Perhaps because cheap, discrete, blue LEDs came before RGB strips, so were an easy option for moonlights?

I'd build my own (Arduino based) controller. I quite like the idea of writing code to mimic clouds, just for the geek-irony of controlling the cloud(s).
You've got me thinking ...
Do you know what LEDs commercial aquarium LED strips use? Do they produce significantly different spectra to those that standard RGB led strips can produce?


----------



## dcurzon (16 Mar 2021)

idris said:


> Thanks. 30 or 60 LEDs per meter?


Im sure it was just 30


----------



## zozo (16 Mar 2021)

idris said:


> Thanks Zozo. _"Why blue?_" is a very good question. Perhaps because cheap, discrete, blue LEDs came before RGB strips, so were an easy option for moonlights?
> 
> I'd build my own (Arduino based) controller. I quite like the idea of writing code to mimic clouds, just for the geek-irony of controlling the cloud(s).
> You've got me thinking ...
> Do you know what LEDs commercial aquarium LED strips use? Do they produce significantly different spectra to those that standard RGB led strips can produce?


I guess so that it still is an old fashion habit from the days we didn't have any decent light control options. Meanwhile, compared to more natural colours blue simply looks actually awful.

Arduino is a very good option to do this, it all is PWM anyway all coded with a pulse length from 0 to 255. I'm very curious about how and what you are planning to make. And with an ESP NodeMCU board, you could even make a WIFI web server on NTP and manage it on the fly. There are quite a few nice examples to find on GitHub. I looked into it, but unfortunately, I lack the skill to make it, but the possibilities are endless.

*








						Build software better, together
					

GitHub is where people build software. More than 56 million people use GitHub to discover, fork, and contribute to over 100 million projects.




					github.com
				



*
Regarding LEDs, I guess you are best off with the regular DC12v constant voltage SMD strips. With RGB it doesn't make that much of a difference. It's the mixing colors that make the spectrum, all 3 colors at 100% is a very cool white color and anything in between also has enormous variation. In most fixed lights they use a fixed schedule with a limited selection of different colors. But as said, if you manage to set each channel separately via PWM from 0 to 255. Then just gave the website I posted above a glance, all colors displayed can be made. Then you only have to figure out how the coding reflects the intensity in percentage. No idea if PWM pulse 127 is 50% of the light intensity in lux of the connected LED.

Anyway, nice experimental project, and very curious about it. Good luck..


----------



## idris (16 Mar 2021)

I'm not thinking of anything too ambitious at the moment. Just a timer with light intensity varying, as you say, with PWM. To simulate clouds is just a matter of some changes in light intensity (simply manipulate variables for the respective RGB outputs) based on some timings. Power it all with a wall watt (and possibly a voltage regulator), bung the arduino outputs through MOSFETs, and Bob's your father's brother.

You could set timings and brightness in conjunctuon with a PCB display, or if you used an apropriate MCU, via a bluetooth app or IOT.

If you've played with Arduinos, it's all pretty simple.


----------



## Maf 2500 (17 Mar 2021)

zozo said:


> ... I'm not sure where the blue light to mimic moonlight came from? Is it the closest thing to give a sense of darkness?
> 
> But since when you go out at a clear full moon night there is nothing blue about the moon and light it reflects.


True, the light reflected by the moon is actually a little redder than sunlight if properly measured, probably due to the colour of the rocks on the moon. The reason people equate blue light with moonlight is because of the Purkinje effect :


> the tendency for the peak luminance sensitivity of the eye to shift toward the blue end of the color spectrum at low illumination levels as part of dark adaptation.


Also, reefers first popularised aquarium moonlighting, I believe, and they tend to favour the blue end of the spectrum due to it penetrating deeper into the sea.


----------



## zozo (17 Mar 2021)

idris said:


> I'm not thinking of anything too ambitious at the moment. Just a timer with light intensity varying, as you say, with PWM. To simulate clouds is just a matter of some changes in light intensity (simply manipulate variables for the respective RGB outputs) based on some timings. Power it all with a wall watt (and possibly a voltage regulator), bung the arduino outputs through MOSFETs, and Bob's your father's brother.
> 
> You could set timings and brightness in conjunctuon with a PCB display, or if you used an apropriate MCU, via a bluetooth app or IOT.
> 
> If you've played with Arduinos, it's all pretty simple.



I played a little on small projects that run in a loop with the ESP8266 and ESP32 and with ATTiny it indeed is all fun and relatively simple and wonderful stuff. The only obstacle I would run into is understanding and compiling relative complex coding if it goes beyond small projects with setting timers and intensities. But that is a matter of studying I yet haven't given myself the time for.

Anyway, if it concerns an open-top tank you could make it even more interesting with several smaller cob-led units functioning as a spotlight. I once did this with 5 units positioned above the tank as an arch. With the far left and right one beaming diagonally into the aquarium and the 3 middle ones straight down. Switching them subsequently on and off from right to left increasing the intensity and numbers of lights as the day progresses and doing the same thing backwards for the night effects. Then the light will not only change intensities but will come from different angles. I did this with fixed colors with 2700K - 6500K and 8000K COB LEDs. Since I did only have 5 channels on the controller. But the effect was rather stunning with the light changing angles casting different shadows arching over the tank back and forth similar as the sun and moon do in nature... Even noticed the fish that like to stay closer to the surface region follow the light play. At first light in the morning coming from the far-right, the fish were schooling in the right side of the tank. And with the first moonlight at the far left, they liked to school at the left side of the tank.  I guess this is a natural behavior and are attracted to light because it makes them see all that falls on the water surface they maybe can eat.


----------



## idris (17 Mar 2021)

Nice idea.
I'm surprised the fish follow the light. From my trout fishing experience, they seem to prefer the safety of the shadows once they're bigger than fry, but I guess there's not so much aerial predation in an aquarium. 

Over night I've remembered I've got a semi functional LED floodlight gathering dust in the garage that I might try and harvest the COB from. I've no idea whether it's viable, but as I really need to get out more ... but can't yet ... it might be worth tinkering with. #donttellthewife


----------



## Zeus. (17 Mar 2021)

Bit late to the party 

I have a Moonlight Passover on my 500L tank which I can activate at any time when lights are off via mobile phone or press of a button on PLC, it is my favourite viewing time, one press when watching film and it runs for set period.

Don't have it set to run daily, just hit the button when it suits, after all we don't get a full moon every night so it felt more natural.


----------



## zozo (17 Mar 2021)

Zeus. said:


> Bit late to the party
> 
> I have a Moonlight Passover on my 500L tank which I can activate at any time when lights are off via mobile phone or press of a button on PLC, it is my favourite viewing time, one press when watching film and it runs for set period.
> 
> Don't have it set to run daily, just hit the button when it suits, after all we don't get a full moon every night so it felt more natural.



We have an old saying that says "A good friend always shows up late." 

And that's a very good point, why waste energy when your not looking at it...


----------



## zozo (17 Mar 2021)

idris said:


> I'm surprised the fish follow the light. From my trout fishing experience, they seem to prefer the safety of the shadows once they're bigger than fry, but I guess there's not so much aerial predation in an aquarium.



There are some videos on youtube, showing how Wild discus are caught, always at night with the use of a Flashlight. In the dark, they seem to feel safer and reside closer to the surface, and seemingly are attracted to the light. But then a Discus is also predatory fish and not really a surface dweller. During the day it stays in deeper parts and can only be caught with a net by chance. Predatory fish are all opportunists that hit and attack out of hiding or out of a very still position.

But obviously, we can't know what and how a fish sees the world around it I'm just trying to make logical sense from an observation. And my best guess is, surface-dwelling fish sp. like to forage from the surface and have learned to follow the light because it makes them see more clearly what lands on this surface. After all, all eyes seem to be light-sensitive receptors. Even a trout comes out of hiding towards the light seeing and to get that fake fly you have presented to it.
That again makes sense seen from the opportunistic behavior perspective of predatory fish, you have to look/hunt for that trout and make it see that fly.


----------



## idris (17 Mar 2021)

Fair point.
Now I think about it, I've a feeling I've heard about using a torch at night as an old poachers trick.


----------

