Hiding Cardinals

[Eoin]

Hi. I have 8 cardinals and 1 pepper cory in my 20 gal aquarium. I have had these cardinals for the better part of 2 years now. Previously they were in the 20 gal with other friendly fish, but I had decided that I wanted to have a tank with purely cardinals.

I have read that cardinals prefer subdued lighting, but this creates some problems. I don’t want to block out too much light as I imagine that wouldn’t be good for the plants. I do expect that the plants will grow up and over the open area in my tank, creating a canopy, but I’m not sure if even that will be enough. I’m also thinking of putting in some kind of temporary canopy over the open area. However, I am again unsure of what results will come. One of the display tanks at my local pet shop has a similar setup to my tank, and all of their cardinals are out and about. I plan to bring in more cardinals once my pet some gets more in, though I am giving serious thought to adding some neon tetras instead (the main reason being that none of the pet stores in town can keep cardinals for more than a few days before they are sold out, and so you never can tell if the group bought in are going to survive for very long).

Does anyone have any ideas of what I can do to remedy this problem? I would really like to actually see these cardinals out of hiding. Thanks.

 

[ScottS]

I keep a dozen in a 20H with no problems. My light is on 12 hours/day and there is no canopy of green between them and the light. You can see the tank in my gallery. It's 2 pieces of driftwood on the bottom, a fake amazon sword to the right, and 4 or 5 fake cabomba plants to the left.

The only other inhabitants are cories and a bristlenose.

Mine got more bold both with time and as I added more. Not much help, but that's all I've had to do to keep them out in the open.

 

[Eoin]

I was just speaking with a woman at a pet shop, and she said that because cardinals are so timid, they often need to see other quiet fish out in the open to feel safe. Sort of a “well if those guys are there, it must be safe to come out”. As we still have room for more fish, I will try that and see what happens.

 

[shawmutt]

I don’t want to block out too much light as I imagine that wouldn’t be good for the plants.

One thing you can do is cut out pieces of construction paper and place them under your light. Strategically placed, the paper will create dark and lighted sections in your tank, allowing your plants to grow while providing hiding places for your fish. As the plants grow, they will create a natural canopy that will take the place of the paper. An idea of the setup is in my gallery. You can also decorate your aquarium in darker colors, such as a black background and/or black substrate. This gives the appearance of a darker aquarium and makes the fish feel more secure without sacrificing light. Another option is to use Black Water Extract, a tinting agent that gives the authentic "black water" look while adding trace elements to the water.

though I am giving serious thought to adding some neon tetras instead

Please be extremely careful if you decide to do this. Preferably put the neons in a QT tank for two weeks. Neons, being mostly tank raised, can very easily be carriers of disease that will wipe out your cardinals. This happened to me--I didn't QT some hatchets I got at the lfs and they introduced ich and wiped out my whole cardinal population.

and she said that because cardinals are so timid, they often need to see other quiet fish out in the open to feel safe

I have to say, I had cories and hatchets with my cardinals, and they still never were as friendly as I had hoped. The only tank I have seen this theory work with is a discus tank with very few hiding spaces. I suppose that if there are not a lot of places to hide for the fish, they eventually get used to big hulking objects in their space, but I never had a chance to try that hypothesis.