# Acclimating Fish - Does light matter?



## JoeRoun (Dec 21, 2009)

*Seems Prudent*

Hi,

I honestly do not know which fish are “super-sensitive,” some are more than others are; I think it is a good policy to keep fish being transported in the dark and to dim the lights while acclimating and upon adding to the aquarium.

I do not know this is any kind of hard and fast rule, it simply seems prudent.

Respectfully,
Joe
FBTB


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## mistergreen (Dec 9, 2006)

Bright light do stress them further. It's ok to leave the lights off for a day or 2.

If the fish is straight from the pet store, I wouldn't worry about it. You can dump straight into the tank.


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## Clear Water (Sep 20, 2014)

After putting the fish in the tank I shut off the light for couple hours to let the fish rest. I also think the drip method is the way to acclimate. Most of the fish I get are in high ph and very hard water. My water is very soft and much lower in ph. So there a lot of the time I take over 1 1/2 hours before the fish are dump in the tank.


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## Knotyoureality (Aug 3, 2012)

Whatever acclimation process you use, reducing light levels reduces activity and stress which can only be a good thing with the stress of the physical changes they're dealing with. Most of my stock are moved to a new container for acclimation and I'll also drop in some floaters or a bit of plant material to provide them some cover as well.


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## Betta132 (Nov 29, 2012)

I just turn off the tank lights for most of the day and then turn them on for a bit so the little things can interact and I can watch them for aggression. 
If I get something from the Petsmart near here (a decent one), I often just dim the lights so I can observe them as they're released. The store is five minutes away, if that, and the transport bags aren't opaque, so they can see light all the way home. If nothing is too nervous, I don't turn the lights off until night.. If I see them acting scared, I turn the lights off.


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## dzega (Apr 22, 2013)

lights off for the day i introduce new fish.
ive tried couple of times without switching them off and seen huge stress difference


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## CAPSLOK (Dec 8, 2013)

It's good practice to put fish in an opaque bag for transport - reduces stress. This can be putting your bagged fish into a paper bag after. Any knowledgeable LFS I've been to automatically does this.

Tank lights should be off when floating bags, also for stress reduction. 

When adding new fish to the aquarium, I think it is good practice to have lights off for the first day - lets new fish get used to the aquarium and also tends to mean that the established fish aren't out and about pestering them. This is even more important with any fish that aren't 100% peaceful to newcomers.


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