[Perri]

Hi All, I'm a new fish owner and new to the forum. Great to meet you! So I got a 5.5 galloon starter kit at PetSmart and three cories. I now realize after being on the forum for a couple of days that this is likely too small a tank for 3 fish? Though they said at PetSmart that was fine and I could even add one.

1) Is it necessary to increase my tank size?
2) Until I can transfer them to a new tank, how often should I change the water? X times per week and 25%, 30%?
3) I have one cory that hasn't stopped moving and two that sit on the bottom. Is this normal cory behaviour? I've seen mixed things online. The water on quick test strips seems fine.

Thank you for any advice!!!

 

[e.shell]

Hi All, I'm a new fish owner and new to the forum. Great to meet you! So I got a 5.5 galloon starter kit at PetSmart and three cories. I now realize after being on the forum for a couple of days that this is likely too small a tank for 3 fish? Though they said at PetSmart that was fine and I could even add one.

I would disagree with PetSmart's advice in most cases, and especially here. Many store personnel are quite knowledgeable and very helpful, many others haven't a clue, but can't stop talking.

1) Is it necessary to increase my tank size?

Yes. The general rule for sustainable water quality is "One inch of fish for each gallon of water." With a heavily planted, and/or well maintained tank, this can be stretched a little, but not much.

Unless you have dwarf corys, your fish will get to be between 1-3/4" and 2-1/2", depending on exact species. 1-3/4" x 3 is 5-1/4 gallons, so you are already at capacity, especially for a new tank.

While there is a guideline for water quality vs fish mass, the other issue that no on seems to recognize is that fish need to feel secure, and they need a certain amount of water depth, floor space (running room) and cover/hiding places to achieve this.

For example, you could have 50 gallons of water, but if it's spread out over a 10 foot square area and is only an inch deep, the fish will live in terror of overhead predators.

Corys can be very shy, and in my opinion, the floor space in a 5.5 gallon tank is not nearly large enough for corys to feel secure, and even a 10 gallon tank is a little small unless there are lots of hiding places and escape pathways.

2) Until I can transfer them to a new tank, how often should I change the water? X times per week and 25%, 30%?

25% a week won't hurt, and if you're not over-feeding them, should be fine.

3) I have one cory that hasn't stopped moving and two that sit on the bottom. Is this normal cory behaviour? I've seen mixed things online.

Considering conditions (new tank, new fish, small area), yes, probably normal. The two that are laying around probably think they're doing their best to hide, while the swimmer is doing what is expected. It is normal for corys to swim for a week or more in a new tank, even if it is heavily planted, with lots of hides and water quality is good. I have seen it many times and have stopped worrying about it.

Good luck,
Ed

 

[Perri]

Thank you so much, Ed! I just posted again yesterday that all three fish now are sitting at the bottom and barely moving, even at night for the last week. The three cories are small right now, probably 3/4 of an inch and there are three different species - green, pepper and albino. Petsmart told me they would school together but alas... I've also never seen them eat. They move if I move the gravel around.

Even if I get a new tank this weekend - I need to let it cycle so hm... Not sure if you have any ideas of what I can do for them in the short term as I remedy the situation. Thank you again!

 

[e.shell]

Probably the best thing short-term is to provide them with some cave-like hides so they can relax. Maybe get something you could transfer over to the new tank with them that they would find familiar. Thin stones or small artificial "reptile hides" can be used to create cavities large enough for all three to get into together.

They seem to recognize the archetypical 'corydora body shape' and accept each other, even though exact species differs. My two species of corys DO school together and have even interbred, although the resulting young seem to be sterile.

Regarding eating: I believe their inactivity is based on trying not to be noticed by possible predators in a new, marginally secure environment - they may consider it too risky to eat during the day, and are awaiting the security of darkness. I have a 40 breeder with 6 or 7 corys in it that I very seldom see. During the day, they spend most of their time in the caves and only come out for live blackworms (almost irresistible). I know they are eating regularly because all of them are quite healthy looking.

You can see the cave where my corys hang out in the center-right of this picture:

For scale, that white tape on the bottom front glass is 2" long and graduated in quarter-inches.

 

[Perri]

This is a beautiful tank! Ok I'm going to get the bigger tank this weekend. I would eventually like to have fish that I can see every once in a while!