Fish afraid of the lights

[Mark Hewitt]

Hi,
I have a 17 gallon (64 litre) tank which is home to 5 black skirt/widow tetras.

Most of the time they are darting about all over the tank quite happily, even though the big one tends to chase the smaller ones!

The problem I have is they don't like the tank lights at all! If I put on the lights that came with the tank "Interpet Bright White Day 15w", they completely freak out and then swim to a shady spot to hide, they then stay there and refuse to budge for hours.. switch the light off and they immediately start swimming about again.

I've also tried with a blue "Cool Blue Moon" light, same result.

Then I tried just an ordinary 7w (35w equivalent) household bulb which they don't run away from immediately but after a minute or two they find a shady spot and again, they don't come out again, not even for food.

It's strange because in the store they were under bright fluorescent lights and they didn't seem to mind at all.

 

[Blueiz]

It's normal for them to be startled by it, they will eventually get used to it. How long have you had them?

 

[Mark Hewitt]

It's normal for them to be startled by it, they will eventually get used to it. How long have you had them?

3 of them have been in there for 3 weeks and a further 2 for 2 weeks.

I've expected them to get used to it, but they just don't, and I don't want to stress them out! One time I left the light on to get them used to it and I couldn't find any of them! Some of them had wedged themselves as far underneath an ornament as they could get!

They seem ok with the table lamp as long as it's not too close to the tank.

 

[dkpate]

Are you letting them get accustomed to the light, and not just lighting the tank light up?

 

[Mark Hewitt]

Are you letting them get accustomed to the light, and not just lighting the tank light up?

It makes no difference as to the ambient lighting at the time, the reaction is the same.

 

[dkpate]

Hmm, that's weird then, I dunno lol.

 

[joy13]

It sounds more like the light is adding to an additional stress. What is your ammonia, nitrites and nitrates? Are you using strips or liquid for tests?

 

[Mark Hewitt]

It could be that. I'm leaving the lights off at the moment while the cycling process completes. (I know with fish cycling = bad!).

But they were like that from the moment we put them into the tank.

I'll try it with them again once my readings are down to zero.

 

[meegosh]

When I upped my lighting to closer to 3 wpg my Angelfish would freak out when I turned the lights on. Now he is fine, after just a few days. I agree that maybe they are stressed and the lights just add to the problem. What are your parameters?

 

[Mark Hewitt]

Now that the ammonia has gone to zero. I've tried them with the lights again, and although they do still prefer not to be in the full glare of it, they haven't reacted too badly.

Having said that, the light I'm currently using is actually a normal household compact flouresent 7W bulb, the type you'd have in a bedside lamp, so it's quite yellow compared to the original 'daytime' bulbs, but it's also a fair bit dimmer so possibly useful for getting them used to things.

Hopefully I'll replace the 7W with the original 15W daylight bulb once they get used to the lights being on.

 

[dkpate]

Sounds good. I got a new tank with a much brighter light, and my loaches aren't out nearly as much now.

 

[Mark Hewitt]

Unfortunately after all this time, the Black Skirts are still terrified of the tank lights. They'll swim about for a short while, maybe 5 minutes after the lights go on, then they'll go and hide or as long as the lights are on, which could be hours.

 

[dkpate]

Maybe you could try the blue lights? I use those on one of my betta tanks, because they don't like light too much.

 

[Mark Hewitt]

Maybe you could try the blue lights? I use those on one of my betta tanks, because they don't like light too much.

Tried that unfortunately. The tank I got came with a 'Bright White Daylight' bulb and a 'Cool Blue Moon' one. They seem to react in exactly the same manner to the blue as they do to the white.

 

[Mark Hewitt]

Having said that, the light I'm currently using is actually a normal household compact flouresent 7W bulb, the type you'd have in a bedside lamp, so it's quite yellow compared to the original 'daytime' bulbs, but it's also a fair bit dimmer so possibly useful for getting them used to things.

I've tried this again. It's a 35W equivalent bulb and the first day they were hiding again, but I've got it on a timer to run for 10 hours a day and by day 3 they were out and swimming around as normal

I'm aware the light is a different colour to the daylight lamps originally in the tank, does it make any difference? We don't have any live plants.

 

[Guyver]

I noticed as I was cycling my 10 gallon last year that the Dalmation Molly that I was using to start it with would freak out if the lights were on, and would do the same every time I walked into the room after being gone for a time. I passed it off as stress from cycling, and sure enough, once my nitrogen cycle was up and running he turned out to be just fine.

 

[Mark Hewitt]

I noticed as I was cycling my 10 gallon last year that the Dalmation Molly that I was using to start it with would freak out if the lights were on, and would do the same every time I walked into the room after being gone for a time. I passed it off as stress from cycling, and sure enough, once my nitrogen cycle was up and running he turned out to be just fine.

Thinking about it, my goldfish did the same thing!
The black skirts don't however, if they see you coming they are right at the front of the tank straight away!

I was thinking of changing the light I have now, which is just an ordinary household light, hence very yellow, back to the proper white aquarium lights, but I actually prefer the yellowish light of the bulb I have now, mostly because it matches all the other lighting we have in the room, so the tank looks like part of it, rather than standing out as some bright white beacon!

 

[rusilja]

Same with my cardinal tetra, when I put on light they mostly hide under my inside-filter or swim low between plants...
After a month or so they get used to it
And they swim freely

 

[Mark Hewitt]

An update. Just moved my fish from my old tank which had 2x 5w CFT household bulbs to a 35g tank with a T8 30W 'Interpet Goldfish' tube. Tried the lighting and the fish absolutely freaked out! Hid as best they could and were still there 20 minutes later when I relented and switched the light off again, at which point they immediately swam out again.

I've already got some floating plants in there and have turned the tube to the dull side to dry to reduce the light but they still hate it!

 

[Mark Hewitt]

Are there such things as opaque condensation trays? I think even if there were (say) black plastic directly below the light so there is no direct illumination there would still be more than enough light in the tank.