Cardinal Tetras behvavior

[WKJR]

I recently added 5 cardinal tetras to my newly cycled planted 20 gallon aquarium. It has been about a week and they kind of just hide behind the plants most of the time and dont do much swimming or schooling. I have checked water parameters and everything is safe. Any suggestions? I am considering adding 3-5 more tetras but did not want to overstock the tank too quickly! Thanks!

[JettsPapa]

Hello,

It's difficult to help without more information.  What size is the tank, and what other inhabitants (fish, snails, etc) are in it?

[WKJR]

20 gallon tank, currently have 3 amano shrimp and 2 cherry shrimp and that is all as far as other inhabitants.

[Brian]

Water parameters are safe….  What do you consider safe?  I would check with the store and ask what they kept them in, and if they had any problems with remaining stock.  Also what is the temperature, cardinal tetras will like it warm (like 83-84).   Light?  Do they act like this all the time? Maybe to much/bright.  Try leaving lights off and room lights on.  

[WKJR]

Ammonia/Nitrites ~0. Nitrates ~5 ppm. Temperature is around 76. Light I try to not have on too long as I read they can be sensitive to bright light so only a few hours a day for my plants but they behave similarly when the lights are off..

[Brian]

Hmmmm, well I would at least bring the temperature up some and talk to the shop/store.  Make sure your water matches the stores.  Is is possible to have a small electrical current leaking into the aquarium?  Are they eating ok?

[WKJR]

ok I will try contacting the store. they are very eager/excited to eat 

[lefty o]

if they are eager eaters, they are likely fine. they do like to be in larger groups, and will probably be much more active in the tank with more friends in the tank.

[WKJR]

ok thats what I was thinking. I will add more soon! Thanks so much for all of the input!

[Wrencher_Scott]

On 5/6/2022 at 8:57 PM, WKJR said:

ok thats what I was thinking. I will add more soon! Thanks so much for all of the input!

I agree with @lefty o 100%. If they love eating they are likely perfectly fine. I would not worry about keeping them in hotter water either. 

Schooling fish are goofy. If there aren't enough they don't feel safe. I would add at least 5 more. I think the rule of thumb is minimum 6 but they are small so I say go higher, lol

Also , Cardinals are black water fish, they need very clean water (lots of bio filtration, as do shrimp). This is way more important than PH or temp. 

[Dandroid]

I have cardinals and they seem shy too.  I did notice though that when my light is dimmer they come out way more.  I have a hygger light that  emulates a sun rise then a sunset.