Tuesday, September 22, 2009

Aquarium Moonlight / Mesečina

English:
Moonlight simulation in aquariums can look pretty astonishing and it is mainly added as a visual effect. According to some research, it can also trigger corals and some fish to spawn, but, to be fair, according to my very experienced friend who is by profession biologist and very devoted freshwater, saltwater and reef aquarist, this fake moonlight effect with couple of LEDs does not have any noticable effect. But never the less, it still looks pretty cool. Well, that counts, too!

Simple moonlight effect can be added to an aquarium using few low-to-moderate brightness blue LEDs (Light Emitting Diode), resistor and a small AC-DC adaptor attached to separate timer. But, even simpler solution is to use factory made Flex LED module with integrated LEDs on a printed circuit board and resistors on a flexible self-adhesive strip. Flex LED strips can be easily shortened into smaller segments to suite your aquarium (the shortest segment is 4.5 cm with 3 LEDs in the model I have used below). In any number of segments we always use the same voltage output (12 Volts DC), which makes it ideal for easy Do-It-Yourself (DIY) aquarium project.

For small and medium home aquariums under no circumstances do not use popular high-power LEDs (few thousands of mili-candela intensity and several Watts in electrical power), since this type of lamps are used to replace regular aquarium lightning, not for moonlight or dawn simulation!

Since there are various types of Flex LED models on the market, your creativity will have to contribute to their variable implementation. I used a simple plastic rod from a drying rack to attach flexible strip to it. Also, you can use plastic circles or any other wave-shaped object. It is also possible to attach strips directly to the aqurium glass, whether from the inner or the outer side. It is really up to you and your taste (or imagination).

Another neat trick you can use thanks to variable DC voltage output from an adaptor is to lower the voltage via switch so you can dynamically adjust your moonlight intensity. No need for cutting segments! More exotic solutions can implement a microcontroller for simulation of moon phases, but as I stated above, all that effort could be a bit pointless.

In my case I used 21 LEDs strip (31.5 cm) which I got from my local electronics shop. They are moderately heated with nominal current supply of 150 mA @ 12 Volts. As you can see from a pictures below, they are very bright with each LED emiting around 200 mC (mili-candela) of light.

Beside Flex LED strip, you will need a cheap AC-DC adaptor for 12 Volts and a timer to program your dawn and moonlight effect. Altought this low-intensity LED light normally does not affect plants and fish population in a negative way, Flex LED with numerous LEDs could be conciderably brighter then few ordinary LEDs, so you should provide a period of complete darkness for a few hours. Below you can see a simple diagram how I did it.


Srpski:
Simulacija mesečine u akvarijumu može izgledati zapanjujuće i uglavnom se postavlja kao vizuelni efekat. Prema nekim istraživanjima, mesečina može doprineti razmnožavanju nekih vrsta riba i korala, ali da budem potpuno iskren, prema mom prijatelju biologu koji je pasionirani slatkovodni, morski i koralni akvarista, ova lažna mesečina sa nekoliko dioda nema gotovo nikakvog uticaja. Ipak, važi da izgleda efektno. I to se računa, zar ne?

Jednostavan efekat mesečine može se postići upotrebom svega nekoliko slabih ili umereno svetlih plavih svetlećih dioda (LED - Light Emitting Diode), redno vezanog otpornika i AC-DC adaptera koji se priključuje na poseban tajmer. Ipak, još jednostavnije rešenje je upotreba Flex LED modula u obliku fleksibilne (savitljive) trake na kojoj je integrisana štampa sa otpornicima i diodama. Flex LED traka se može seći po potrebi na manje segmente (najkraći segment je 4.5 cm sa 3 diode kod modela koji sam ja upotrebio). Bez obzira na broj segmenta, Flex LED se uvek napaja preko napona od 12 volti, što dodatno pojednostavljuje samogradnju.

Za manje i srednje kućne akvarijume nikako ne smemo koristiti popularne "high-power" diode (nekoliko desetina hiljada mili-kandela intenziteta svetla i nekoliko vati električne snage), jer se ove diode koriste kao zamena za regularno osvetljenje u akvarijumu, a ne simulaciju zore i mesečine!

Obzirom da na tržištu postoje različiti Flex LED modeli, vaša kreativnost treba da vam pomogne u njihovoj implementaciji. Ja sam, konkretno, upotrebio plastičnu dršku ofingera na koji sam zalepio fleksibilnu LED traku. Takođe, možete upotrebiti plastične krugove (tacne) ili bilo koju talasastu formu da biste pričvrstili diode i sprečili njihovo kidanje.

Da biste prilagodili intenzitet mesečine, ne morate nužno skraćivati Flex LED traku. Dovoljno je da na AC-DC adapteru smanjite izlazni napon i time ćete već postići slabiji intenzitet uz ravnomernu disperziju svetlosti duž čitavog akvarijuma. Egzotična rešenja mogu sadržati i mikrokontroler sa simulacijom različitih faza meseca, ali kao što sam na početku rekao, sav taj trud može biti nepotreban.

Konkretno, Flex LED za moj akvarijum sam nabavio ovde (može se naručiti pouzećem proizvoljna dužina trake tj. broj segmenata). Pri naponu od 12 volti 21 dioda zahteva 150 mA struje (ili 20 mA po segmentu), a to može zadovoljiti i najmanji AC-DC adapter koji se može uzeti na pijaci. Sa slike ispod se može videti da su vrlo sjajne sa svojih 200 mC (mili-kandela) intenziteta svetlosti po diodi.

Pored Flex LED trake, trebaće vam i tajmer kako biste isprogramirali simulaciju rane zore i mesečine. Iako plavo LED svetlo slabog intenziteta normalno ne ometa ribe i biljke u svom ciklusu, poduža Flex LED traka može sadržati poprilično dioda, pa je potrebno isključiti ovo osvetljenje i obezbediti period potpunog mraka. Ispod je dat raspored osvetljenja u mom slučaju.







2 comments :

  1. I made the sunlight from LED segments. Very cheap, one segment has 3 LEDs, I used 9 in total. Right now use this light from 21-24. Its nice to us at home but in same time its safe to fishes if using appropriate blue LED light - watch how many nanometers has the light!
    Astalavista!
    Sjohund

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  2. LED segmente ubaci u komad providnog creva koje silikonom zalepis za haubu. S jedne strane ostavi otvor za struju, a sa druge zadihtuj. Veoma cisto i efikasno!
    Poz,
    Gedza

    ReplyDelete