New Corydoras Owner Questions

[Zonotrichia]

We bought 6 Corydoras sterbai last week, and I have fallen head over heels in love with these little guys. It's always been our goal to have corydoras since starting our tank in the beginning of 2020, but we ended up putting it off for a long time due to an endless cycle of guppy problems—we just didn't want to add them into what seemed like an unstable environment. Our 29 g is now home to a single seemingly healthy male guppy (knock on wood), and we decided that it was time to get our corydoras!

Our little school is currently in a 10 gallon cycled quarantine tank, with the aim of adding them to our planted, sandy 29 gallon once their 4 weeks in QT is up. I can't wait to see them swimming around the 29 g and playing in the sand.

I have two questions:

1) We have been feeding them Hikari sinking wafers, and I'm a little confused about how many wafers we should be feeding per day. The packaging says to "Feed the amount your pet will completely consume in 20 minutes." The thing is, it takes them far longer than 20 minutes to eat 1 pellet! It takes them a while to realize that the food has been dropped, and it's not like they're all descending like a pack of wolves once they notice it. It seems unlikely that 1 pellet is all they would need? Any advice would be appreciated!

2) For the most part they are schooling happily, racing around and sifting through the bits of sand and detritus in our QT. Sometimes in the morning they are piled up on each other like a bunch of kittens—except for one. One of the corys (I'm assuming it's the same one, but I can't really tell them apart) seems to often be separated from the group. If 5 are all sheltering around the sponge filter, the loner will be in the opposite corner of the tank. If 5 are loafing out in the open, the other will be hiding behind the sponge filter. They'll school together sometimes, but one seems to always be separated from the pack when they are resting. Is this something to be concerned about, or just normal behavior?

Thanks!

(Pictures included just 'cause they're cuties.)

 

[Tigerburp]

We bought 6 Corydoras sterbai last week, and I have fallen head over heels in love with these little guys. It's always been our goal to have corydoras since starting our tank in the beginning of 2020, but we ended up putting it off for a long time due to an endless cycle of guppy problems—we just didn't want to add them into what seemed like an unstable environment. Our 29 g is now home to a single seemingly healthy male guppy (knock on wood), and we decided that it was time to get our corydoras!

Our little school is currently in a 10 gallon cycled quarantine tank, with the aim of adding them to our planted, sandy 29 gallon once their 4 weeks in QT is up. I can't wait to see them swimming around the 29 g and playing in the sand.

I have two questions:

1) We have been feeding them Hikari sinking wafers, and I'm a little confused about how many wafers we should be feeding per day. The packaging says to "Feed the amount your pet will completely consume in 20 minutes." The thing is, it takes them far longer than 20 minutes to eat 1 pellet! It takes them a while to realize that the food has been dropped, and it's not like they're all descending like a pack of wolves once they notice it. It seems unlikely that 1 pellet is all they would need? Any advice would be appreciated!

2) For the most part they are schooling happily, racing around and sifting through the bits of sand and detritus in our QT. Sometimes in the morning they are piled up on each other like a bunch of kittens—except for one. One of the corys (I'm assuming it's the same one, but I can't really tell them apart) seems to often be separated from the group. If 5 are all sheltering around the sponge filter, the loner will be in the opposite corner of the tank. If 5 are loafing out in the open, the other will be hiding behind the sponge filter. They'll school together sometimes, but one seems to always be separated from the pack when they are resting. Is this something to be concerned about, or just normal behavior?

Thanks!

(Pictures included just 'cause they're cuties.)

I usually crush up and soak pellets to make it easier for corys to eat so might want to try that, and if the lone Cory isn’t showing signs of sickness there isn’t anything to worry about

 

[Katie Dawn]

Congrats on your new littles!

I agree that the 20 minute rule doesn't work at all. Some of them won't even come out to check out the food within 20 minutes. I've heard a general guidance that if you feed fish at night and it's basically gone in the morning then you're feeding a pretty good amount. I often see little bits leftover in the morning, but by the time I feed them that night they've pretty well cleaned all the bits up too, and that seems to work for me!

 

[CMT]

If he looks healthy otherwise, I wouldn't worry about the loner. I have a Cory that acts that way too. He'll join the school from time to time but he's his own guy. He's also grown to be the biggest of my group.

The timing rule doesn't work with bottom feeders. I think you just have to feel it out. If there is food in the morning, you fed too much. I'd start with 2-3 of those wafers for a group of 6 and go from there, but it's going to vary. With only one other fish, you shouldn't have much other food for them to clean up, so they may be able to take more.

My corys love the shrimp pellets too.

Enjoy...they really are a great fish.

 

[DoubleDutch]

Variate in food and add a thin layer of sand in the qt tank.

 

[Zonotrichia]

Thank you for the advice, all! I've started crumbling up the sinking pellets and also supplementing with bits of Hikari Vibra Bites, which they seem to be enjoying. I also added a small amount of sand into the tank (really a very thin layer from my main tank, which is in need of new/replacement substrate, so not much to spare), and it has definitely brought them out of hiding more! I was getting a little worried that they were hiding so much over the past couple of days, and the sand seems to have made the more comfortable.

Today I found one resting on a fake plant leaf, which made me panic for a moment—flashbacks to my guppy die off, when I kept finding them resting in plants or on the substrate before passing But he swam down once I dropped fish in, so I think he's just being lazy. I have to get used to fish that just like to lie around!

 

[Linda1234]

I usually adjust feeding based on fish behavior. Hungry fishes will get quite aggressive at eating; non hungry fishes will still eat just more lazily. I tend to mix up my food (including the hiraki pellets) on a daily basis. Sometime i feed them shrimp pellets (omega-one); sometime spirulina flakes but just a little each day unless they get super aggressive at eating. I would put in no more than 2 pellets and one is probably plenty.

 

[Katie Dawn]

I don't think your corydoras is being lazy, he just knows the best places to relax.

Glad to hear things are going better for you! When you're able to add a good layer of sand (an inch or two) they will love that! They dig into the sand looking for food, often digging so deep their entire face is covered! Gotta love 'em!

 

[Zonotrichia]

We moved our Corydoras sterbai into the 29 g in December, and they've been getting acclimated to their new home over the past couple of weeks. The tank is now home to 1 guppy, 1 mystery snail, and the 6 corys. Our guppy is a voracious, greedy little thing who is used being an only fish, but we seem to have figured out a feeding strategy to make sure that the corys get their share.

All seems well for the most part, but my one concern is that they are very skittish and shy! I'll notice them sifting through the sand in the front of the tank when I'm watching from another room, but the minute I walk closer, they will zip away in a panic. Funnily enough, they were much more active and outgoing when we first added them in the tank. Now when I am sitting in front of tank, 90% of the time they are all hiding behind the sponge filter and amazon sword in the back corner. The main time that I see them is during mealtimes, where they do come out, hoovering the sand as they march in a little line along the edge of the glass.

I've attached a picture of my tank. Do you think there are sufficient hiding places here, or is there something that I can do to make it a more cory-friendly environment?

Parameters:
pH 7.4
Ammonia 0
Nitrites 0
Nitrates 5
3 dKH
9 dGH

 

[Linda1234]

I've have 7 sterbai in a 29 for the past 3 years and they are still very skittish. My tank has more hiding places than yours but it doesn't really help much; if i'm not near the tank they come out and are quite active but the minute i walk over (even when feeding the fishes) they get quite skittish.

I've been told that eques are a lot less skittish; but they are fairly expensive.

 

[DoubleDutch]

The issue could be the combination of light colored sand and bright (LED?) light from above. Get some floaters and more plants that grow allong the surface. That might solve things.

In my case the albino sterbai seem to be more at ease than the normal ones hahaha.

But it is quite strange sometimes that Corys can change in behaviour for quite unclear reasons. In one of my tanks 5 trilineatus are hiding since we added 3 new ones to the two who were in ?????

 

[Linda1234]

The issue could be the combination of light colored sand and bright (LED?) light from above. Get some floaters and more plants that grow allong the surface. That might solve things.

In my case the albino sterbai seem to be more at ease than the normal ones hahaha.

But it is quite strange sometimes that Corys can change in behaviour for quite unclear reasons. In one of my tanks 5 trilineatus are hiding since we added 3 new ones to the two who were in ?????

yea i had that problem with orange laser; i had 6 fearless orange laser cory; then added 4 skittish ones and they have all been skittish since then. Not sure the light helps with sterbai; I keep my tank fairly dim and the top is covered with hornworth and jungle val 2 inches deep; but they are still pretty skittish. I think the problem is the males are esp skittish and once they begin to scatter the females follow them. I've found this before that it really only takes one fish in the tank to be skittish to trigger everyone fleeing in panic.

 

[Zonotrichia]

We added our school of 9 harlequin rasboras to the tank last night, and while I don't want to jinx the tank, they seem to have brought my corys out of hiding a little! Honestly this is the first time in a while that I've seen all 6 of them whuffling out and about in the front of the tank, and it wasn't even feeding time. They are still skittish if I make a sudden movement or dare to take a picture, but this is a definite improvement! The dither fish effect? Crossing my fingers that this trend continues

 

[Wideglide]

You said it, dither fish effect. Changed my tank and I love my Danios

 

[Zonotrichia]

I noticed some weird splitting happening on one Cory’s barbels yesterday, which is kind of alarming! It almost looks like they are fraying, but they are still very long—longer than the other corydoras’ barbels. If anyone has had experience with something like this, I made a thread in the fish disease subforum. Thank you in advance!