Cardinal Tetra 55 gallon

[Oli]

So I’ve finally given up with cichlids. I love how much personality they have but I have always wanted a heavily planted tank and despite trying a number of times (much against everyone’s advice ) it has never worked. Since I started my first big tank i have had Severums, Acaras, Angels, Geophagus etc. I have always had 2 angelfish. They have been my prized possession and today I gave them away. The reason being is because I always end up coming back to cardinal tetras. I think they look absolutely stunning. This week I gave away my Acaras and introduced a load of cardinals, unfortunately the angelfish were all over them, so I decided to commit to the cardinals and remove the angels. It was sad because they were my first fish, but I am now committed to a peaceful, planted tank.

Currently I have around 20 cardinal tetras, 10 Congo tetra juveniles, and 2 Pearl gouramis. As much as it looks great and all is peaceful, I am considering going all out on cardinal tetras and removing the rest. I think it would look great to see a heavily planted tank packed with cardinals. My question is how many could I get away with…tank is a 4ft, 55 gallon. Over filtered and planted (Not as heavily as I’d like yet but I’m getting there).
Thanks!

 

[Byron]

I think your tank will be the envy of many members.

First suggestion...floating plants. Most all forest fish prefer darkness to overhead light, but cardinals (Paracheirodon axelrodi) very much more so. Baensch & Rhiel termed it a light phobia. Studies have shown that in the habitats where sunlight hits the water, this species will not venture into it, but remain under the shadow of floating vegetation or overhanging terrestrial vegetation. It was observed that there was a distinct line, and the fish never ventured even 1-2 cm across it into the light. This would have quite an impact on their stress level.

Your Congos are similar, but do you really want to get rid of them? They are beautiful! And with floating plants, you will have hours of interactions with males and females. Same holds for the pair of Pearls; I think you have an incredible setup here, bit obviously the fish inhabitants are your call. Just think it through very carefully!

 

[Oli]

I think your tank will be the envy of many members.

First suggestion...floating plants. Most all forest fish prefer darkness to overhead light, but cardinals (Paracheirodon axelrodi) very much more so. Baensch & Rhiel termed it a light phobia. Studies have shown that in the habitats where sunlight hits the water, this species will not venture into it, but remain under the shadow of floating vegetation or overhanging terrestrial vegetation. It was observed that there was a distinct line, and the fish never ventured even 1-2 cm across it into the light. This would have quite an impact on their stress level.

Your Congos are similar, but do you really want to get rid of them? They are beautiful! And with floating plants, you will have hours of interactions with males and females. Same holds for the pair of Pearls; I think you have an incredible setup here, bit obviously the fish inhabitants are your call. Just think it through very carefully!

I’ll be sure to get some floating plants on the go asap! While I do love the Congo’s and Pearls, I worry if I am maybe becoming overstocked. I have read congos can hit 4” and I am desperate for more cardinals, I want the whole tank to shimmer.

I also find that while the congos and Gouramis are stunning when the light hits, especially up close, from a distance on my couch, they are a kind of grey/silver colour and a little bit boring.

How many more Cardinals (if any) do you think I could get away with. I wouldn’t be opposed to maybe dropping the congos down to 5/6 if it would help?

Thanks for the advice

 

[Byron]

Floating plants allow fish to become more intensely coloured. This is a natural response because they live in shaded water and use colouration in spawning and communication. I had a group of ten Congo in a 4-foot tank, and they absolutely shimmered with iridescent colours of the rainbow.

You are no where near over/fully stocked. Nine Congo, 2 Pearls, 24 Cardinals (what I was able to count) is a beginning. With substantial floating plants (Water Sprite, Frogbit, Water Lettuce, and/or the red Tiger Lotus allowed to form floating leaves) you can double and triple numbers so far as fish the size of the Cardinals are concerned.

Do not decrease the Congos below the nine. This will have significant repercussions and cause stress. Scientific studies have now proven that shoaling fish should be in groups no less than ten, preferably more; the identified effects smaller groups have was remarkable, from increased aggression, to tighter shoaling, to even a latency to feed. The latter is a clear sign that to the fish this is a very serious issue, when they are hesitant to feed because of too few of them.

 

[Oli]

Oh wow, the online stocking calculator everyone seems to use says I am well overstocked! I also read a lot of things that said Congo tetras in a 55 gallon is pushing it as it is!

You’ve always seemed very knowledgable however and I’m glad to here I could add a load more cardinals. In that case I am likely to look at adding an extra 12 every week until around 50-100?

I will keep the congos at 10 and add some floating plants !

 

[Byron]

Oh wow, the online stocking calculator everyone seems to use says I am well overstocked! I also read a lot of things that said Congo tetras in a 55 gallon is pushing it as it is!

You’ve always seemed very knowledgable however and I’m glad to here I could add a load more cardinals. In that case I am likely to look at adding an extra 12 every week until around 50-100?

I will keep the congos at 10 and add some floating plants !

Increase the cardinals in stages, say 10-12 at a time, and give it a few weeks. At some point you may decide things are the best they can be and not want more. I'm not sure I would go with 100 here, in fact I know I wouldn't, though not exactly because of fish load but just the fish. If you have too many of one species, you begin to not see their beauty but just a mass, if that makes any sense.

No calculator can be relied upon simply because stocking is not a case of fish mass/volume, but the inherent needs of each species. Congo tetra are not suitable for tanks under 4-feet, but I have twice had them in 4-foot tanks, once in the 1980's a 55g, the other more recently in a 90g. The length is what matters, not the width or the depth, nor the volume. They like to swim; mine held relay races all the time, it was a joy to behold. Two males, sometimes a third would join in, racing from one end to the other side by side, then a brief pause, then back they raced. The other fish were untroubled by this, and it certain brought out the beauty of this species.

Having the proper numbers of a shoaling species, having sufficient space to allow them to be themselves as nature programmed them, and not having to be afraid of any tankmate. This is what matters, along with appropriate water parameters, lighting, water movement, and any hardscape the species may require--like floating plants!

 

[Oli]

Great, thanks for the info! I’ll check out some floating plants at some point this week and maybe grab myself another 10 cardinals

 

[emeraldking]

So I’ve finally given up with cichlids. I love how much personality they have but I have always wanted a heavily planted tank and despite trying a number of times (much against everyone’s advice )

Welcome to TFF top start with...
Have you ever thought of keeping dwarf cichlids? For those can be kept in a planted tank without any problems.

 

[itiwhetu]

For me, the Cardinals will never breed. So, I would have the tank set up so the Congo's will. You need about 50% of the tank volume in plants. Then just let them go for it. If you want to breed any fish don't add Cichlids, unless they are Discus. Discus just want to socialize so don't care about the fish in their tank.