Fish Behavior And Dim Lights?

[WhiteRabbit]

I have a tank that I got from a friend filled with 6 cardinal tetras (plus a few others). After setting it up in my home, I noticed that the tetras hid in the bottom back corner under some plants, and for the most part never came out. However, I recently changed the hood light to a blue and white fluorescent, and now the tetras seem to be out and about quite a lot. My question therefore is, are my fish now out because the light appears dimmer? I have read 'here and there' that fish prefer dim light, but how true really is that?

Many thanks from someone trying to learn.

 

[Marve99]

Different fish behave differently in different light conditions - don't keep tetra so not sure about them.


Did you cycle ths tank?

 

[OldMan47]

Welcome to the forum WhiteRabbit.
Each fish species has its own response to bright lighting. In my tanks, many of the fish seem to be fine with the brightest lights that I have for them and others hide with rather moderate lighting. You are now the local expert on the particular fish that you have. They are fish that come out more often when the lights are dim.

 

[WhiteRabbit]

Different fish behave differently in different light conditions - don't keep tetra so not sure about them.


Did you cycle ths tank?

Well I got it from a friend. He had it for over two years and all we did was do a massive water change the day I got it. Of course, that probably freaked-out the fish but still, I am pretty sure the tank was overstocked in the past and the fish may have been under stress for a long time. The newer fish don't behave like that. Perhaps I need to get the tetras a fish shrink

 

[chrisrm]

how long have you had them?

it might just take some time for them to adjust!

 

[WhiteRabbit]

how long have you had them?

it might just take some time for them to adjust!

The fish have been under my care for a month now. I have done various things, some have helped, some not. I added an air stone for starters. The tank is a 5 gal one-piece unit with hood. Not much air gets in there and it made sense to put as much Oxygen into the system as possible. That at least helped remove the fishy smell the water seemed to have. I then added more wood and plants. A nice willow moss was added to help sop up extra nutrients. I also changed out the biofilter media, which was over two years old. However, most of that didn't get those tetra out of their closet corner.

Then I did something I probably should not have done, I added more fish. I put in 10 Rasboras and 5 Phantom Tetras and two Mollies. I am a beginner so I didn't realize I was over stocking the tank. Still, my thinking was that I had to retrain these darn fish to swim around the tank, and I figured they might pick up things from the newer fish. That did improve things a little. I did see the cardinals out more than before. Finally, I changed the standard white light to blue white. That seems to have made the biggest difference and now the Cardinals (Rummy Nosed too) venture out and swim around all the time. The color patterns also seem brighter and healthier.

The problem is, it is hard to tell what is really going on. This is not science and I can't test the affects of each change. All I can really do is look at the state of things and decide if I like it. At this point, the tank is overstocked and the water smells a bit fishier than it used to. I do frequent water changes and test to see if the chemistry is good. So far, so good but I did lose the mollies that I moved in.

Oh well, wish we luck guys.

 

[OldMan47]

OK so we are now at 6 cardinals, 5 phantoms and 10 rasboras in a 5 gallon tank. The only question in my mind is which fish will die off next. My guess would be the cardinals are next. The rasboras are tough and with the cardinals gone they will likely be able to survive for the long haul. I have no experience with the phantoms so I don't know if they are as tough as the rasboras.

 

[WhiteRabbit]

OK so we are now at 6 cardinals, 5 phantoms and 10 rasboras in a 5 gallon tank. The only question in my mind is which fish will die off next. My guess would be the cardinals are next. The rasboras are tough and with the cardinals gone they will likely be able to survive for the long haul. I have no experience with the phantoms so I don't know if they are as tough as the rasboras.

Yes! The Death Tank!

Actually, I moved out 4 Rasboras and 2 Phantoms to another smaller tank I have. Total in this 5 gal tank now is;

6 Cardinals
3 phantom
6 Rasboras
2 guppies (forgot about them)

This is a ticking time bomb, and I am aware of it. The obvious answer is to get a bigger tank. I am working on that. Hopefully, I can get a 20 gal (or bigger) set up and cycled before more deaths occur.