How important is ramp up > peak > ramp down?

[happyhourhero]

If I bought an 8 bulb fixture and didn’t have the ability to ramp it up or down, is it really that big of a deal? Would I just run a shorter photoperiod?

 

[Phildago]

I think ramping up is fairly important, ramping down not as much

 

[CNDReef]

We used to turn on mh and turn them off without a issue

 

[AdamB]

I don’t think it’s that’s big of an issue really . I had t5’s on first tank without ramping and my tank looked great !

 

[Quietman]

I came this close to going with on/off T5. Still might on next experimental build. Too many gorgeous tanks with simple on/off T5 or Halide. I think it's more for us than the inhabitants. Not like 'shimmer', now that's critical for livestock and not a marketing thing at all (because I need to tell my wife I need a $400 light for some good reason, right?)

 

[Aardvark1134]

For 3 decades or more peope did not use any ramp up or down. So clearly its not critical

 

[Daddy-o]

If I bought an 8 bulb fixture and didn’t have the ability to ramp it up or down, is it really that big of a deal? Would I just run a shorter photoperiod?

Do they all turn on at once or do you have more than one switch?

 

[MnFish1]

I dont think its a big deal - mainly because if you look at the Templates for radions - they do it both ways. I personally like the ramp up though

 

[Bpb]

It is absolutely zero deal. Plenty of evidence as to the fact that it doesn’t matter at all, and nothing more than speculation and assumption as to why it IS important

 

[Wolverine47]

Ramp up/down is more for aesthetics and allowing us to view our tanks in different lighting and enjoy the tank longer since you typically will have something like an hour on each end for ramp up/down so it allows viewing of tank longer

 

[Phildago]

I'm guilty of this speculation.

What my speculation is based off of is that since some corals are active at nighttime and extend clear tenticles it may be possible for the bright light to burn these unprotected appendages. Pure speculation, but also plausible.

 

[djray77]

I wonder the same thing as with ramping up and down flow.

 

[MnFish1]

I'm guilty of this speculation.

What my speculation is based off of is that since some corals are active at nighttime and extend clear tenticles it may be possible for the bright light to burn these unprotected appendages. Pure speculation, but also plausible.

I think you're incorrect - only because of this - think of 'the wild'. in our tanks the 'ramp up and down' comes from 'above' in the wild it goes from east to west - and minute by minute - certain parts of the coral goes from 'shadow' to 'full sun'. Its for this reason - I dont believe its 'important'.

That said - I recently changed my tank from a 'slow ramp (natural daylight' - to a more sudden blue - white - and had problems - I did some other things - so I have no clue whether it was that or something else - but - My guess is - any sudden change (on a day to day basis - not a minute by minute basis) - can cause problems

 

[Dana Riddle]

It takes about 20 minutes for photosynthesis and protective processes to ramp up (see directions for PAM fluorometers.) With that said, corals/zoox can see sudden increases in light intensities - think of a heavy cloud cover breaking at noon and resultant increase in light intensity. But, on a very practical level, and as others have stated here, we had no ramping with metal halides back in the day. Not an issue IMHO.

 

[Phildago]

I think you're incorrect - only because of this - think of 'the wild'. in our tanks the 'ramp up and down' comes from 'above' in the wild it goes from east to west - and minute by minute - certain parts of the coral goes from 'shadow' to 'full sun'. Its for this reason - I dont believe its 'important'.

That said - I recently changed my tank from a 'slow ramp (natural daylight' - to a more sudden blue - white - and had problems - I did some other things - so I have no clue whether it was that or something else - but - My guess is - any sudden change (on a day to day basis - not a minute by minute basis) - can cause problems

I agree that this could be correct and for sure exaggerated... I don't think anything over a half hour could have additional benefit really. But even in the wild, shaded areas still get some light come morning time, enough that would likely make them retract vulnerable structures. If these structures even are vulnerable.

The only reason I've speculated this is because these tentacles are never exposed during the day, but always exposed at night.. So it must be related to the light. Whether that is simply an evolved characteristic due to the food availability or for defense, I do not know.

It really could go either way... But people make a good point about metal halides being fine with on and off, so that's pretty good evidence for calling bs on ramps

 

[Bpb]

Forget metal halides. It takes my halides a solid 4-5 minutes to go from dark to full strength and it is perfectly linear and gradual. It appears to be a quick ramp. Certainly not just dark to surface of the sun in the blink of an eye. Look at the people who run T5’s. Pop them on and they’re bright basically instantly. Maybe 30 seconds and they’ll get 20% brighter as they heat up.

 

[Magellan]

We used to turn on mh and turn them off without a issue

I still do that. 8hrs a day every day

 

[oreo54]

Do it for the fish.....................

 

[MnFish1]

Do it for the fish.....................

Do what for the fish? I agree that it can be stressful for the fish if they go from total darkness to 100% light - but dont most people have their lights turn on after at least some 'morning light' is present. At night. Agree it can also be stressful to shut lights off suddenly to total darkness. When I was doing it like that I would leave the room light on for 5-10 minutes - and it never seemed to be a problem (if you meant something else - Sorry - just didnt understand yoru comment)

 

[FishDoc]

If I bought an 8 bulb fixture and didn’t have the ability to ramp it up or down, is it really that big of a deal? Would I just run a shorter photoperiod?

I would argue not nearly as important as we think and certainly not as important about peak spectrum, parr or duration of the light supplied.