Mimicking Photo Period

[Matthew5664]

When ajusting timers for daylight saving do you take into account the hours of daylight are longer in the summer than in the winter?

Meny tank reviwes I've read have a set photo period aposed to a seasonal changing one?

I ask this in relation to the spawning of fish and inverts because I've read that seasonal changes in light and temp can effect this??

[kim]

I don't think they have daylight saving in the tropics ?

:)

kim

[Matthew5664]

Surly there is some differance in the daylight length?

[Tiggsy]

when the tank is so far removed from the wild does it matter?

tank lighting is changing dependant on room lights, tank lights, TV on, etc, etc

[Matthew5664]

alright alright, sorry for asking

[zimreef]

I think it is a valid question :) .

A real luxury, but sfiligoi lighting systems have an option where you can program a particular longitude and latitude and it emulates the lighting periods accordingly. However, in the tropics, the summer/winter light difference is very small compared to here - a difference of perhaps an hour or so over the year so not worth bothering about.

For our purposes I agree with Tiggsy - we generally have the lights switch on in the afternoon and switch off at midnight for our viewing convenience and as long as that is suffcient to provide enough for our corals, that's fine.

Moonlight is another matter though and emulation of the relevant lunar cycle together with slight changes in temperature have, as you say, been shown to initiate coral spawning behaviour.

Cheers

John

[Matthew5664]

Thank John, thats what i thought. I think I will move my moon light from my FW tank over to my SW tank for the corals when I have some ( got 1 Zoo at the mo Hiked on some LR might spred)

Do you think it's trile and error with the lighting periods? ( sun and moon ) is there a ratio to go by?

[zimreef]

No, it's not trial and error - your main lights will be pretty constant anyway. It will be difficult to emulate the lunar cycle without computer control as the luminance and photoperiod change every night. I don't have any facts and figures to hand so need to research a bit more unless someone else volunteers the info :) . Some good books will help - I think you'll find information in both the "Delbeek and Sprung" and "Fossa and Nilsen" series.

I'm not sure of the benefits though. Corals don't have to spawn to be healthy - most corals will "frag" more successfully than produce "babies" by spawning. Secondly, I understand that some tanks have been wiped out by various corals spawning so perhaps not a good thing overall. <_<

Yes, I understand that in theory the closer we emulate nature the more chance of a thriving ecosystem, but not sure of the so-called benefits in this case.

John

[Matthew5664]

"I understand that some tanks have been wiped out by various corals spawning so perhaps not a good thing overall. "

Did't know that! wow think I'll stick with the moon light for viweing only

As for fraging is this common? Is it due to specific conditions of does it happern when they 'feel like it'??

[zimreef]

"Fragging" is the label used when aquarists cut a segment off a coral and milliput it onto a rock and grow a whole new colony. This happens in nature with for example storm damage (not the milliput bit obviously) where branches are broken off and ultimately grow into a new colony. The term "accidental fragging" is used tongue in cheek to denote being a clumsy b****r when doing tank maintenance and breaking off bits accidentally :lol: .

HTH

John

[Matthew5664]

LOL I see....

I was under the impression that the coral thought I know I brake of a part of me and woner off down the tank and set up a new home!!!

I'm new to this can you tell??

I thought that mitosis had something to do with it but now I know. Thanks John.

When 'Fraging' can you just hack a bit of?

[Mandarin]

you have to be carefull when 'hacking' corals up. on leather corals you cant cut into the main stem it will damage the coral and all in all it depends which bit you cut from what species.