Shy Cardinals!

[MBStevens]

Got a few new cardinal tetras to add to my school the other day; now there's at least 13 or so. They've been oddly shy all of a sudden since adding them and taking away the cherry barbs that were fighting in here before (I don't like aggression in my tanks, so as sad as I was to lose them, I took them back to the LFS to hopefully be happier in another tank). I thought getting a bigger school would make them even more comfortable but it somehow did the opposite. Now they hide all the time; I can barely even get anyone to come out and eat food. They will only approach food when I'm far away from the tank (by then of course it's basically on the substrate). I'm confused by this suddenly shy behavior. The only thing I can think of is the cherry barbs must have been serving as a dither for the cardinals.

My hope has been to eventually get a pair of German Blue Rams in here. I wondered if getting the rams would likely help the cardinals, if they can serve as a sort of reverse-from-typical dither fish. Usually cardinals are suggested as a great dither fish for rams, but I'm wondering if it could potentially go the other way too. Thoughts?

What I've done to try to help the cardinals so far is add some floating plants (salvinia), lower the light intensity down 5% on my fluval 3.0, and put a sponge intake on my hob to slow the flow rate. I'm thinking my next tactic is to try getting a dither fish. Have considered some pygmy corydoras. But I don't want to add too much really as the GBRs are my ultimate goal. (It's a 20 gallon so there's size limitations.) 

I'm super disappointed by how shy these guys are; they are stunning and my tank looks gorgeous with them in it but I can't enjoy them this way! 

[Fish Folk]

I think that if you give them time, they’ll grow accustomed to their space. Feeding live bbs can bring out their spunkiest personality. They do work fine with Rams and Discus.

Here’s a couple videos where Rams & Cardinals shared a 29 gal.

 

[Huck]

On 7/15/2021 at 6:34 PM, MBStevens said:

Got a few new cardinal tetras to add to my school the other day; now there's at least 13 or so. They've been oddly shy all of a sudden since adding them and taking away the cherry barbs that were fighting in here before (I don't like aggression in my tanks, so as sad as I was to lose them, I took them back to the LFS to hopefully be happier in another tank). I thought getting a bigger school would make them even more comfortable but it somehow did the opposite. Now they hide all the time; I can barely even get anyone to come out and eat food. They will only approach food when I'm far away from the tank (by then of course it's basically on the substrate). I'm confused by this suddenly shy behavior. The only thing I can think of is the cherry barbs must have been serving as a dither for the cardinals.

My hope has been to eventually get a pair of German Blue Rams in here. I wondered if getting the rams would likely help the cardinals, if they can serve as a sort of reverse-from-typical dither fish. Usually cardinals are suggested as a great dither fish for rams, but I'm wondering if it could potentially go the other way too. Thoughts?

What I've done to try to help the cardinals so far is add some floating plants (salvinia), lower the light intensity down 5% on my fluval 3.0, and put a sponge intake on my hob to slow the flow rate. I'm thinking my next tactic is to try getting a dither fish. Have considered some pygmy corydoras. But I don't want to add too much really as the GBRs are my ultimate goal. (It's a 20 gallon so there's size limitations.) 

I'm super disappointed by how shy these guys are; they are stunning and my tank looks gorgeous with them in it but I can't enjoy them this way! 

I agree with the other answer about time. It takes time for fish to get comfortable. I would not change anything in the tank for a few weeks and see what happens. 

 

Regarding the feeding, you could maybe try hatching some baby brine shrimp. The bbs are irresistable to most fish and since they are live they won't sit on the bottom rotting. They can survive for a good while in fresh water. 

 

All in all, unless you are seeing some indication of health issues, I think time is the way to go.