Cardinal tetra behavior?

[Chrona]

Hi all, this is my first time posting on these forums, but I've been raising fish for a few years now, and I'm stumped about cardinal tetras. My 15 gallon currently contains 1 quarter-sized angelfish (never seen any aggressive behavior), 1 platy, and a chinese algae eater (very small, going to transfer to my 55 gallon when/if he starts getting territorial. I started building up a small group (5) of cardinal tetras, with plans for getting maybe another 4 or 5 for a nice shoal. One of the smaller ones died about 4 day after I put them in the tank (wasn't eating anything), but health wise, all of the other tetras seem to be doing great...rich color and lots of energy. The problem, it seems, is that now, the four remaining fellas now essentially pick corners, and for the most part, stay at the bottom of the tank. If anyone goes in another corner, he/she is promptly chased away. Is this normal behavior for groups smaller than 6? Furthermore, they seem excessively jittery, as in, they will all dive into the cave for several minutes at the slightest outside disturbance (ie flakes being dropped into the tank), though they jump in and out to grab a bite to eat

All of the tetras are about an inch+. I've had them for 3 weeks or so, and have done two 25% water changes since then. The tank is fairly well planted, with some rock caves, and I'm using a 7 watt florescent tube.

I've never kept cardinal tetras before, so I just wanted to get this cleared up before I get any more of them. After all, they don't look very pretty guarding their corner most of the time ;)

Thanks very much for any help. I realize this was a fairly long read, hehe

[Lady Hobbs]

I would not be a bit surprised if that angel is terrorizing them at night.

[Chrona]

Thanks, I'll try quarantining the angelfish for a few days. Although he really is a small one, the angel's body is only as long as the cardinals.

Although, would having more cardinals also do the trick? Power in numbers? This is my first time with small shoaling fish. I've mostly had goldfish and angelfish

[Lady Hobbs]

Then, I wouldn't bother. Not likely a very small one would bother them. It may be just because there is so few of them that they don't feel safe. I have 6 neons that hang on the bottom all the time, too. I think if I had many more they'd be more active. Darned things cost $2.59 each. You'd think as small as they are, you could get them for a buck.

[Chrona]

Haha, I feel ya. Neons cost the same here in Connecticut. Cardinals are 2.99 though, and on a college students budget......I mean, each of those babies could buy 3 packs of ramen noodles!

I will get a few more and see how it turns out. Thanks again for the help!

[Drumachine09]

Haha, I feel ya. Neons cost the same here in Connecticut. Cardinals are 2.99 though, and on a college students budget......I mean, each of those babies could buy 3 packs of ramen noodles!

I will get a few more and see how it turns out. Thanks again for the help!



Ramen Noodles are the Friggen Bomb digitty. The Savior of all college kids!!!

I belive Jeff has had experiance with Cardinals, you might want to pm him.

[jeffs99dime]

welcome to a.c. first off. what is your ph, hardness?

[Drumachine09]

Oh yea, Welcom to the A.C.

[Severus]

Welcome to AC

[Chrona]

pH - about 6.2

Hardness - I haven't tested this in a while, but I always use those rechargeable softener pillows for water changes/replacements since I have hard well water. It should be very soft though, or else the minerals would buffer out the acid right?. I just tested the pH this morning.

Gonna run to the pet shop sometime this weekend. Hopefully they've got some decent size cardinals.

Oh, and thanks to all :)

[Chrona]

Well, I'm up to 6, and it's still the same situation....well...more fish = more fighting now...lol

Basically theres 1 in each corner with 2 staying together around the middle. Today, I saw one of the original cardinals nip at the Angelfish when I was feeding them. THAT was a surprise!

I mooched a water test from my local fish shop, and as I suspected, the hardness is about where it should be with a dGH of 4. pH hasn't changed either. Although the water started getting a little murky. Not sure why, because my ammonia/nitrite/nitrates were all fine. Water clarifiers didn't do anything either.

What I really need is liquid Ritalin for fish I think....T.T

[wijnands]

I've had cardinals for ages. Just started with a new shoal last month. I've never seen this kind of behaviour in them. Even when at one time I only had a pair of them left Time for some group therapy?

[Chrona]

The aggression seems to have gone down a bit after I took out the angelfish and the siamese algae eater and replaced them with a dwarf gourami and 2 oto cats. I actually added 2 more cardinal tetras (for a total of 5) before that, and they chased each other around even more, lol.

[Chrona]

Funny how things go round circle. This was my first post, and I've finally been able to crack the puzzle. Turns out Hobbs was right all along. After taking the angelfish (and the SAE) out, the cardinals have now calmed down and are schooling peacefully, with no fights even after feeding, which is when they used to be the rowdiest. My guess is that, even though I never saw the angelfish case after the tetras, the mere presence of a predator stressed the cardinals, resulting in some irregular behavior. I'm relieved that it wasn't an overcrowding issue.