Cory inactive and staying at the bottom of tanks and platy bullying

I have 6 sterbai cory who are usually so active and always swimming up and down and dancing in the current.. well for the last 2 days they are just inactive and are sat together at the bottom of the tank all day. They are still eating and there is absolutely no physical signs of illness or damage to them

The only new thing in the tank is some guppy grass for fry which has been loosely planted at the back of the tank which is where they used to spend all their time swimming back and forth, up and down.. there is still room for them to do that though!

Also I have 3 platies (1 male, 2 female) the male is a bully and is clearly intimidating one of the females (the other female I think is pregnant and she can seem to hold her own and often chases him away) and the Male seems to then take it out on the other female and bully her. She is not eating and just stays low trying to hide ..

I’ve tested my water - 0 ammonia, 0 nitrite, 20ppm nitrate. PH is the same as it’s always been (around 7.4-7.8)

I don’t know what to do! Any one have any ideas what is going

 

Sounds like they’re just stressed out from the new plants. If they’re still acting like this a week after the plants went in I would look into this more, for now just let them adjust

 

Sounds like they’re just stressed out from the new plants. If they’re still acting like this a week after the plants went in I would look into this more, for now just let them adjust

Thank you for your reply!

Poor things, I worry that maybe they feel they haven’t got enough space to swim around?

This is a picture of the full tank (looks much smaller on the picture than it is) and I’ve just added a bit of guppy grass along the back..

 

Thank you for your reply!

Poor things, I worry that maybe they feel they haven’t got enough space to swim around?

This is a picture of the full tank (looks much smaller on the picture than it is) and I’ve just added a bit of guppy grass along the back..

Don’t worry, they have room My fish have just started to go near some plants I added in too!

 

Don’t worry, they have room My fish have just started to go near some plants I added in too!

Thanks! That makes me feel much better. I will still keep a close eye on them.

What do you think about the platy?

 

Thanks! That makes me feel much better. I will still keep a close eye on them.

What do you think about the platy?

Are you able to separate her or get more females? It sounds like she’s not getting a break so more females hopefully should divert his attention

 

How often are you doing water changes? How much do you change each time? How long has it been since you did your last one? Anytime I see any kind of behavior that seems off the first thing I reach for is my water changing equipment. Your numbers look good but they don't tell the whole story. There are things that build up in our tanks we don't normally test for. Something may be spiking and causing what you are seeing. A water change might help and as long as the fresh water is dechlorinated and temp matched it for sure it won't hurt.

 

How often are you doing water changes? How much do you change each time? How long has it been since you did your last one? Anytime I see any kind of behavior that seems off the first thing I reach for is my water changing equipment. Your numbers look good but they don't tell the whole story. There are things that build up in our tanks we don't normally test for. Something may be spiking and causing what you are seeing. A water change might help and as long as the fresh water is dechlorinated and temp matched it for sure it won't hurt.

I do about 40% water change weekly & I last did a water change on Thursday.. I will do another tomorrow and hope that helps! I could do with removing most of the decorations (rocks, driftwood etc) and doing a good gravel vac but I don’t want to stress them out any more

I usually gravel vac the areas I can easily get to around the front but haven’t done a full gravel vac for a while.. what do you think I should do?

Are you able to separate her or get more females? It sounds like she’s not getting a break so more females hopefully should divert his attention

Unfortunately I don’t have means to separate her he doesn’t try to mate with her (he did at first, but she must have already been pregnant because a few days later I discovered a baby!) the baby is still alive and getting bigger each day! But now the momma doesn’t look good, she doesn’t seem to eat and is always trying to hide away.. it’s like the ‘alpha female’ tells the Male off, and he goes and takes his anger out on the other female! It’s really sad to see

 

Unfortunately I don’t have means to separate her he doesn’t try to mate with her (he did at first, but she must have already been pregnant because a few days later I discovered a baby!) the baby is still alive and getting bigger each day! But now the momma doesn’t look good, she doesn’t seem to eat and is always trying to hide away.. it’s like the ‘alpha female’ tells the Male off, and he goes and takes his anger out on the other female! It’s really sad to see

You could try swapping out the male or getting more females. Other than that, more plants would help.

 

I do about 40% water change weekly & I last did a water change on Thursday.. I will do another tomorrow and hope that helps! I could do with removing most of the decorations (rocks, driftwood etc) and doing a good gravel vac but I don’t want to stress them out any more

I usually gravel vac the areas I can easily get to around the front but haven’t done a full gravel vac for a while.. what do you think I should do?

It sounds like you are doing a good job with the frequency and amount of water changed so what you are seeing may not be caused by a buildup of anything. It is a good idea to clean under decor from time to time though. There could be quite a buildup of waste under the decor and getting it out of there might not be a bad idea. Maybe though instead of doing all of it at the same time you could clean under one thing each week and just keep rotating. That way hopefully it will be less stressful for your water pets.

I just though of something. My corys don't seem to be as active during the warmer months of the year. If it is summertime where you are is your tank a bit warmer than normal?

 

It sounds like you are doing a good job with the frequency and amount of water changed so what you are seeing may not be caused by a buildup of anything. It is a good idea to clean under decor from time to time though. There could be quite a buildup of waste under the decor and getting it out of there might not be a bad idea. Maybe though instead of doing all of it at the same time you could clean under one thing each week and just keep rotating. That way hopefully it will be less stressful for your water pets.

I just though of something. My corys don't seem to be as active during the warmer months of the year. If it is summertime where you are is your tank a bit warmer than normal?

Thank you for your reply! That is a good idea to do a section a week and rotate round!

It actually has cooled down from a heatwave we had last week.. it was hot and I was having to float ice packs to keep the temp down but they actually were fine and acting normal then and now it has cooled down again. It’s just strange because they were so active and the past 2 days haven’t been (along with my platy bully!) makes me worry something is wrong..

I have been watching them a lot and getting really good close looks at them and there really is nothing I can physically see on any of my fishies of concern.. hoping it is just a bit of an adjustment period? Really hope so as I love my corydoras so much!

 

Maybe it’s the opposite reaction to the temp? Increased temp makes the metabolism work harder and they would want to find more food, so they’d be busy scavenging. Cooler temps typically make animals rest (think hibernation, or humans during winter). Just a thought I have nothing to back it up :3

 

Maybe it’s the opposite reaction to the temp? Increased temp makes the metabolism work harder and they would want to find more food, so they’d be busy scavenging. Cooler temps typically make animals rest (think hibernation, or humans during winter). Just a thought I have nothing to back it up :3

Yeah true... it’s all just a bit strange. They are definitely still eating (they are greedy!) I will just keep a close eye on them.. if it was just them acting differently I would be less concerned.. it’s the fact the platies seem to all be at each other’s throats! My shrimp have been out exploring all areas of the tank which they hadn’t done so far searching for food even tho I feed them loads (a good sign I hope but whenever behaviours change I always get paranoid - still new at all this!) Sorry I am probably being a little OTT I just really don’t want to lose any more fish

 

I think behavior changes are the first sign Or a good sign of illness, so definitely Not OTT to be concerned. I have a lot of behavior threads as well! But with a good water change schedule, a cycled tank, and no known changes or additions, the lack of symptoms makes it impossible to know what it could be. So yeah, just keep doing the good stuff you’re doing and keep an eye out.

As for the platy issue, if the female is really upset and hiding and not eating, and additional line of sight blockers don’t help, I would look into rehoming since you can’t add more females. Best bet is to rehome the male and stick to all females, especially if you don’t have plans for all the 100’s of babies you’ll be getting soon.

 

I think behavior changes are the first sign Or a good sign of illness, so definitely Not OTT to be concerned. I have a lot of behavior threads as well! But with a good water change schedule, a cycled tank, and no known changes or additions, the lack of symptoms makes it impossible to know what it could be. So yeah, just keep doing the good stuff you’re doing and keep an eye out.

As for the platy issue, if the female is really upset and hiding and not eating, and additional line of sight blockers don’t help, I would look into rehoming since you can’t add more females. Best bet is to rehome the male and stick to all females, especially if you don’t have plans for all the 100’s of babies you’ll be getting soon.

Thank you, that makes me feel better! I’ll just keep watching my water babies and hope they pick up soon!

With the platies - They’ve been doomed from the start .. I wanted and asked for 2 females and a male, got them in the tank and realised I actually had 2 males and a female, thought I’d see how they go but the males started fighting so I returned one of the males for a definite female. All was well and the male was loving life! They all seemed happy and got on ‘swimmingly’! Now they all hate each other! I don’t know what has changed but the original female has been pushed out and she just looks so sad and hides. Nothing outwardly showing anything signs of illness but she just is clearly not happy. And I’ve seen the Male be a bully! I wanted to try and raise some fry as it is the sweetest thing I’ve ever seen! But you are right I may need to rehome my Male! As the original female gave me a surprise fry already! And the second female I think is pregnant now so that leaves me some chance of raising SOME fry (hopefully!!)

- sorry for my rambling hilarious

 

Just an update in case anyone comes across this thread -

I did a large water change (about 70%) and gravel vac a larger area than usual to get up waste that had accumulated under the driftwood and my Sterbai seem a lot happier and are back swimming in their usual spot! They are probably still a little less active and still rest on the bottom a little more than they did before but I’m so glad to see them acting a little more normal!

Unfortunately my female platy died I really am at a loss as to why.. she was absolutely fine and had no visible signs of illness. The only thing is the last couple of days she was clearly being bullied by the male platy. Could stress have caused death that quickly?

Any other theories?

 

I am happy to hear that your corys seem more comfortable.

Sadly sometimes we lose fish. Lots of the time we never find out why. A month or so ago I lost my female pleco. She seemed fine and I woke up one morning to find her floating. She showed no signs of anything wrong with her before or after death.

 

I am happy to hear that your corys seem more comfortable.

Sadly sometimes we lose fish. Lots of the time we never find out why. A month or so ago I lost my female pleco. She seemed fine and I woke up one morning to find her floating. She showed no signs of anything wrong with her before or after death.

You were right about water changes often helping a lot of situations! They almost immediately perked up! Maybe they just needed that extra large change & the gravel vac

Yeah I’ve lost a lot of fish since I first set up my tank and could usually understand why or what happened (newbie errors!!) but now that I have a fairly good understanding of everything and my water parameters are good it is almost even more upsetting when one randomly goes because there is no apparent reason

Anyway fingers crossed we are back to a happy, healthy tank!! Thanks for your help & advice!