Who Gives A Fish Forums

Just got my 55 gallon planted tank fully cycled and stocked. Running a Fluval 407, CO2 injection, and a Nicrew light. Plants are thriving but my Cardinal Tetras seem a bit shy. Any tips to make them more comfortable?

Congrats on the setup! Cardinals can be skittish at first. Try dimming the lights a bit or adding some floating plants like Frogbit. They'll feel safer with more cover. What's your water temp at?

Cardinals prefer softer, acidic water. If your pH is above 7, consider adding some Indian Almond Leaves. Also, ensure your tank has plenty of hiding spots like driftwood or dense plants like Java Fern.

Feline wrote: ↑Mon Jun 16, 2025 1:50 pm Cardinals prefer softer, acidic water. If your pH is above 7, consider adding some Indian Almond Leaves. Also, ensure your tank has plenty of hiding spots like driftwood or dense plants like Java Fern.

Agreed. I'd also check your ammonia and nitrite levels just to rule out any spikes. How often are you doing water changes?

Yo, my Cardinals were the same way at first. Took like a week for them to chill. I added some more tankmates like Corys and they started acting normal. Maybe they just need some buddies?

Mine were shy too. I turned down the flow on my filter and they seemed to relax. Maybe your Fluval is too strong for them?

Yeah, flow can freak them out. I've got a spray bar on my 407 to diffuse the current. Works like a charm.

Floating plants are a game-changer. My Cardinals love hanging out under the roots. Also, try feeding them at the same time every day. They'll start associating you with food.

Dude, same thing happened to me. I added some Blackwater Extract and they perked right up. Also, keep the room quiet for a few days. Loud noises can stress them out.

Cardinals are sensitive to changes. If you've recently added them, give them time. Ensure your water parameters are stable and avoid sudden movements near the tank.