How long do you keep the lights off after introducing new fish?

[Lennie]

I wonder everyone's opinion on this one.

If you do, how long do you keep the lights off when you introduce a new fish to your tank or when transferring your fish into a new tank? Do you keep it off during acclimation period or just after putting fish in the tank?

If you don't, have you ever experienced it causing extra stress?

Do you keep lights off for shrimps and/or snails too?

Share what works the best for you! 

Edited April 5 by Lennie

[lefty o]

i have never kept the lights off when introducing new fish. never seen a problem with it.

[Pepere]

When I get shipped fish, or bring some home from fish store I put them in a quarantine tank ave the lights off until the next morning.

I introduce fish from Quarantine to display tank. In the evening with dimmed light that automatically dims to shutting off and comes back on 8 hours later in the morning.

[jwcarlson]

I don't worry much about it personally.  Usually I try to do it just with room lights.  But some "higher value" fish that I'm introducing I really want to see how they're reacting and it can basically be impossible with the lights off depending on the setup.

[Val]

When I introduce fish to the quarantine tank, I cover it with a towel for a day or two.  Best place for my QT is in the kitchen, so there's plenty of light.  When I move to the main tank, I typically do it in the evening and the lights will be off.  I will turn on the lights the next day (but it's usually just in the afternoon/evening) so fish will have 20 some hours in the main tank sans lights.  After that, I've never noticed a problem.

[BeeGryphon]

When I got mine it was always in the afternoon and I turned off the light for acclimation then just left them off for the rest of the day. I'm not sure they would have cared one way or the other, they were all really active the day I brought them in. I wonder if it's more important for shipped fish that have been in the dark for a couple days?

[Lennie]

Just like I expected, everyone has a very unique way! 
 

I’ve just noticed that I forgot to share my own. As I keep all my tanks in my room, I drip acclimate with a black cover on top of bucket. Then when I introduce new fish to the tanks, I turn off all the lights of all tanks and curtains. Then after half an hour or so, I let some daylight to slide in. After an hour, I generally turn the lights on. 
 

I don’t turn lights off when I introduce snails but I do the same for shrimp

[Guppysnail]

I leave the tank lights off while floating to temp. I have lots of emergent plants so it’s still bright from those lights just not the spotlight affect from the tank light. 
Once the fish are in the tank I feed a little. Then when they are comfy and checking out their new digs I turn the light on if it’s still time for them to be on. I leave it off if it’s past time to turn them off. 
I see no difference either way. Introducing food right away is always key for my new kids to settle in real quick. Hungry kids forget about being stressed and worry over who gets more grub. 

[Fish Folk]

I prefer muting lights rather than going all dark. I am kind of cheesy . . . I use black cupboard liner pieces under my lights to mute them 😂

[nabokovfan87]

On 4/5/2023 at 6:34 AM, Lennie said:

If you do, how long do you keep the lights off when you introduce a new fish to your tank or when transferring your fish into a new tank? Do you keep it off during acclimation period or just after putting fish in the tank?

Overnight.  I tend to check on the fish manually.  I'll use a flashlight, blue lights, and just check on them after a couple hours.  After that, normal light operation the following day.

Shrimp yes, they are light sensitive, especially neos.  I tend to turn the lights off because I don't want the other fish bothering them when they are trying to just get into the surroundings and figure out territory.