dmm28

I've had my 6 cardinals for almost as long as I have had my tank and right from day one they've always stayed in one corner of the tank near the back next to the heater. I've tried turning the heat up a bit to see if that might stimulate them but nothing..........

It's a 75 gallon with 11 black neons, 7 cherry barbs, 1 dwarf gourami, 4 pepper corys,1 otto, and 1 royal pleco as tank mates.

They do from time to time venture outside their perimeter but very rarely. I thought about putting a few more in to see if that might help but I decided to ask here first. Also they do eat well but never really leave their space to do so unless it's for blood worms then they'll go almost anywhere!

Nick G

Have you watched them at night? Some Tetras prefer the dark and only come out when the lights are off.

TFA101

you could add a few more, about 3 or 4 since they have such a small bioload. do you have a tank background? many fish feel safer with a tank background (particularly one with plants on it) that doesn't make them fell exposed on all sides and makes them fell like they always have a place to retreat. Your could also try adding some more plants in the tank as shelter so the feel more secure

dmm28

My tank is almost fully planted there is lots of shelter for them but,..... I do not have a background. I never really thought about that before, I just loaded my tank with plants and thought that they would assimilate to their surroundings.

agabr123

since you have so much space, i definitely agree with TFA101 if you're willing to get a few more, it will make them feel more comfortable in such a large space

Dozey

I have a background and wondered the same thing about my neons. Although I have fake plants I have a lot of them. When the neons were in my 10 gallon q-tank with no décor they swam all over the tank. Now in my main tank they still swim around but keep to the décor. And their only tank mates are a clown pleco and a snail so they certainly don’t have any need to hide. But maybe they figure why take the chance in the open when we have so much protected area to swim in.

I’m really hoping that my Gouramis (quarantined) like the open space. It sure would be nice to see fish in my tank.

cerianthus

Compared to other tetras, Cardinals seems to be less active except when fed. Even when kept in school of few hundreds, will form cluster and stay in one area. Moved little as cluster rather than constantly swam back and forth like danio, especially in well planted tank. Ive seen more movement (swimming) in bare tank with less in group (maybe due to nervousness).

Cardinals are found in calm water rather than fast flowing water where danio are found.

capekate

IMO it sounds like something is scaring your cardinals into staying in one corner and not venturing out into the tank. I dont know what fish it can be or if it is in fact another fish or group of fish. Im wondering if it can be the group of black neons that may be scaring them? In the last two years my group of cardinals has dwindled down to just two. Even in such a small 'group' (hard to call two of them a group lol) they swim all over the bottom of the tank. Cardinals however hardly venture much above the mid level of a tank. I have my guys in with some big fish and they are not insecure at all. So it is my thought that a species of fish in your tank must be making them feel very insecure with the need to hide. Adding more may not remedy the situation since you have six of them in there already. Also, my cardinals never go to the surface to feed and only get what drops to the bottom of the tank. They are so small that is is very hard to tell if they are eating at all, but after worrying about this, I have to assume to live for two years, they have to be eating lol..
Best of luck with your cardinals, they are truly great little fish and when I find more I hope to up the numbers in my tank.