Cories dying again

[Byron]

I risk that because the cories are dying out and I may not keep more. I already have another tank that the betta will go in. My betta is female, so I thought it would work out, but I knew I was taking a chance because the platies share the same space.

Didn't realize the betta is female...but your experience suggests they too can be trouble. On the cories, they would benefit from a sand substrate, they feed by filtering sand, and with gravel cannot do this. So keep that in mind going forward. Good luck.

 

[VioletThePurple]

Didn't realize the betta is female...but your experience suggests they too can be trouble. On the cories, they would benefit from a sand substrate, they feed by filtering sand, and with gravel cannot do this. So, keep that in mind going forward. Good luck.

I would get a more natural substrate, but my dad won't let me. He doesn't believe it's necessary.

 

[DoubleDutch]

I was afraid someone was going to say that that's why I didn't want to mention too much about my stocking, but I was prompted multiple times. I know a betta and platies aren't the best combination, she's going into a 5 gallon once its cycled. You mentioned the water is soft, any way to harden it? I didn't think the stocking was too bad because I put it into a stocking calculator, and it all read as fine.

My cories are dying off, my betta is being moved, and the platies don't have hard enough water. What do I do, completely start over or just throw the tank out? These fish were all recommended for beginners on multiple online sites and the aquarium stocking calculator had no problems.

Uhhhhh are you serious? Are you withholding information cause you're afraid someone will tell you there is something wrong.

Isn't that the other way around when asking for help on a forum ?

The fish you've have are quite bullitproof (besides the betta maybe) so "beginnersfish" as you call it. That still means they have their needs and can't always be kept together when those needs aren't the same.

The peppered Cory is a cool water fish and the betta a warmwater fish.

The peppered in the pic seems to miss his barbels I'd say. I think the substrate chosen is probably culprit of that. Food will get out.of reach and.pollute the lowest warerpart and cause bacterial growth etc.....

Clean out the tank, add a sandbottom, replant and choose fish that more.or.less.have the same needs.

And last but not least : When having problems again, provide the right and all info.available. On this forum and in real life. Otherwise other people won't be able to help you.

 

[VioletThePurple]

Uhhhhh are you serious? Are you not withholding information cause you're afraid someone will tell you there is something wrong?

Isn't that the other way around when asking for help on a forum?

The fish you've have are quite bulletproof (besides the betta maybe) so "beginners' fish" as you call it. That still means they have their needs and can't always be kept together when those needs aren't the same.

The peppered Cory is a cool water fish and the betta a warmwater fish.

The peppered in the pic seems to miss his barbels I'd say. I think the substrate chosen is probably culprit of that. Food will get out.of reach and.pollute the lowest warerpart and cause bacterial growth etc.....

Clean out the tank, add a sand bottom, replant and choose fish that more.or.less.have the same needs.

And last but not least: When having problems again, provide the right and all info.available. On this forum and in real life. Otherwise, other people won't be able to help you.

I can't add a different substrate, my dad won't let me otherwise I would. The temp is usually around 78F to accommodate for everyone's needs. I just wanted to avoid being lectured, sorry if that sounds silly but that was the reason.

 

[Oblio]

I can't add a different substrate, my dad won't let me otherwise I would. The temp is usually around 78F to accommodate for everyone's needs. I just wanted to avoid being lectured, sorry if that sounds silly but that was the reason.

While sand is better for Corys, other substrate will not doom them if kept in good water conditions. Unless you rehome your solo Cory, I would add more after your problems are sorted out. I've had my Corys on a non-sand substrate for about a year and they are doing fine, I do plan to change to sand in the future though.

 

[VioletThePurple]

While sand is better for Corys, other substrate will not doom them if kept in good water conditions. Unless you rehome your solo Cory, I would add more after your problems are sorted out. I've had my Corys on a non-sand substrate for about a year and they are doing fine, I do plan to change to sand in the future though.

Thanks. I hate this because I've had this exact problem before, and it happened again. Groups of cories die out, leaving one survivor. I get more a while later, new group dies again, and the same survivor is left behind. I might just try again one more time and if it happens for a third time, I'll stop keeping cories sadly though I like them a lot.

 

[Byron]

Some in this thread do not understand the needs of Corydoras fish. Obviously something is killing them and it may very well be rooted in the gravel substrate.

Corydoras will not be "fine" over gravel. There are a couple of reasons. First, as another member mentioned, bacteria. The larger the grain size of the substrate, the more harmful bacteria will occur in that substrate. Sand avoids this, assuming proper maintenance. With gravel as large as in the photo here, it is impossible to keep it safe for substrate fish. This is a major cause of barbel erosion, and this problem is clearly evident on the cory/cories in the photos. Another substrate problem also causing barbel erosion is roughness; this can occur with sand too, obviously, but not if the sand is the right type. The gravel here may or may not be rough, but that is frankly immaterial since it is "gravel" and therefore a likely source of serious problems. Which as I say, is certainly the case. This may well be why the cories have died, but not the upper fish.

Second, Corydoras have an inherent expectation to filter feed. They take up a mouthful of substrate, filter out any food they find, and expel the sand out via the gills. They do apparently swallow some sand, according to the stomach contents of wild cories. They cannot feed properly with a gravel substrate. I do not understand the thinking of any aquarist who cares so little for their fish that they refuse to provide what the fish needs to be "normal" and "healthy." If such behaviour was directed at a dog the SPCA would be alarmed. Poor fish have to accept this and make do. Evolution has programmed these fish to feed the way they do, and it is inhumane to deny them that basic need.

There is also evidence in the photos of less than good water. The cloudiness and algae present indicates (probably) high organics and light. The organics is back to the gravel problem again. Please do not acquire more cories unless you change to sand; aquarium sand is safe (provided it is inert--some will raise GH/KH/pH) or a quality play sand like Quikrete Play Sand available from Home Depot and Lowe's in NA. Rehome the lone cory, it is likely to succumb to the same problem in time. The new fish likely did not manage as well because of the stress of being new.

 

[VioletThePurple]

Some in this thread do not understand the needs of Corydoras fish. Obviously, something is killing them, and it may very well be rooted in the gravel substrate.

Corydoras will not be "fine" over gravel. There are a couple of reasons. First, as another member mentioned, bacteria. The larger the grain size of the substrate, the more harmful bacteria will occur in that substrate. Sand avoids this, assuming proper maintenance. With gravel as large as in the photo here, it is impossible to keep it safe for substrate fish. This is a major cause of barbel erosion, and this problem is clearly evident on the cory/cories in the photos. Another substrate problem also causing barbel erosion is roughness; this can occur with sand too, obviously, but not if the sand is the right type. The gravel here may or may not be rough, but that is frankly immaterial since it is "gravel" and therefore a likely source of serious problems. Which as I say, is certainly the case. This may well be why the cories have died, but not the upper fish.

Second, Corydoras have an inherent expectation to filter feed. They take up a mouthful of substrate, filter out any food they find, and expel the sand out via the gills. They do apparently swallow some sand, according to the stomach contents of wild cories. They cannot feed properly with a gravel substrate. I do not understand the thinking of any aquarist who cares so little for their fish that they refuse to provide what the fish needs to be "normal" and "healthy." If such behavior was directed at a dog the SPCA would be alarmed. Poor fish have to accept this and make do. Evolution has programmed these fish to feed the way they do, and it is inhumane to deny them that basic need.

There is also evidence in the photos of less than good water. The cloudiness and algae present indicates (probably) high organics and light. The organics is back to the gravel problem again. Please do not acquire more cories unless you change to sand; aquarium sand is safe (provided it is inert--some will raise GH/KH/pH) or a quality play sand like Quikrete Play Sand available from Home Depot and Lowe's in NA. Rehome the lone cory, it is likely to succumb to the same problem in time. The new fish likely did not manage as well because of the stress of being new.

I thought they could sift through the gravel for food, I watch them do it all the time. I never said I didn't care, I'm just a little confused and I realize I need more knowledge on the subject. I have the light on for seven hours per day. I do regular water changes and tests came up fine.

You're stating that they could be dying from starvation or bacteria in the gravel. I can't fully replace the gravel because I'm afraid that would cause too much harm to the beneficial bacteria or in general. I could get sand on top of it, would that work?

You mentioned that I have to be specific about certain sands to get, and that I could get play sand. I'll have to explain the situation to my parents so they can get the sand. If it's that urgent, I'd love to get sand.

 

[Byron]

I thought they could sift through the gravel for food, I watch them do it all the time. I never said I didn't care, I'm just a little confused and I realize I need more knowledge on the subject. I have the light on for seven hours per day. I do regular water changes and tests came up fine.

You're stating that they could be dying from starvation or bacteria in the gravel. I can't fully replace the gravel because I'm afraid that would cause too much harm to the beneficial bacteria or in general. I could get sand on top of it, would that work?

You mentioned that I have to be specific about certain sands to get, and that I could get play sand. I'll have to explain the situation to my parents so they can get the sand. If it's that urgent, I'd love to get sand.

I was directing my comments as much if not more at some other members in this thread too, just so you know it was not a hammering on you.

I doubt starvation was the issue, and obviously any hungry fish will poke into the substrate for food. But with gravel it is physically impossible for these fish to filter feed, and that is an instinct in their genetics that must be provided for if the fish are to be in good health. About 90-95% of all diseases we encounter in aquarium fish are due to stress. The pathogen/parasite or whatever may bee present, but fish that are not under stress will in the majority of cases fight it off. Fish in the habitat would have disappeared long ago if this ability was not the case. So avoiding stress is clearly the only good road to healthy fish. Stress weakens fish, slowly usually, and there are no visible (to the aquarist) signs until it has almost too late, and in some cases even then it is not obvious...the aquarist says "my fish just suddenly died, why?" but most of the time the underlying reason causing stress becomes apparent. Stress is caused by any un-natural condition. This is why we continually advise that one must research the habitat conditions so we can provide as close as possible. Only by giving the fish what they "expect" can we be reasonably certain they will be "fine." We cannot talk to them to find out how they feel, and visible signs of trouble are often unobserved or may not even be visible.

Replacing the substrate can be safely done, I did it many years ago after I learned the benefits of sand. Your fish numbers seem to be few now, so it would not be too onerous. I won't go into all that, but if you intend cories you need sand, plainly stated. I could see the difference in my 60+ cories when I did this, on the advice of Heiko Bleher. We all learn throughout our time in this hobby.

 

[Deleted member 149562]

To do a partial beach is easy. This is my method, other people do it other ways but I have had success with mine...

First of all - during water change - get a 2 litre size empty plastic bottle (water or fizzy pop - if ex fizzy pop make sure you wash out thoroughly). Cut off the bottom of the bottle and remove the cap at the top.

Then turn the bottle upside down and push down into the water, use the neck of the bottle to gently move the gravel away from an area of approximately 20-25% of the total exposed part of the substrate.

Once you have made a space in the gravel in this way, you can then hold the bottle still upside down about 1 inch maximum above the gap in the substrate and with help from mum or dad, very very slowly and gently pour the sand through the bottle, slowly moving it around the area that you cleared of gravel until that area is covered in sand.

Do not do this more than 1 inch above the substrate surface as it helps keep the clouding to a minimum...the closer the bottle, the better.

Once you have done it, your Cories will have their sandy beach to play, sift for food and to rest upon without having to break down the entire aquarium or remove everything first. Once the sand is in place, refill the aquarium as you normally would at a water change.

Time taken is around 30-45 minutes...you can do it on your own but an extra pair of hands is always useful when pouring sand through the bottle. Its very easy, saves alot of time and the Cories will love their new beach area to feed, relax and play.

 

[AdoraBelle Dearheart]

To do a partial beach is easy. This is my method, other people do it other ways but I have had success with mine...

First of all - during water change - get a 2 litre size empty plastic bottle (water or fizzy pop - if ex fizzy pop make sure you wash out thoroughly). Cut off the bottom of the bottle and remove the cap at the top.

Then turn the bottle upside down and push down into the water, use the neck of the bottle to gently move the gravel away from an area of approximately 20-25% of the total exposed part of the substrate.

Once you have made a space in the gravel in this way, you can then hold the bottle still upside down about 1 inch maximum above the gap in the substrate and with help from mum or dad, very very slowly and gently pour the sand through the bottle, slowly moving it around the area that you cleared of gravel until that area is covered in sand.

Do not do this more than 1 inch above the substrate surface as it helps keep the clouding to a minimum...the closer the bottle, the better.

Once you have done it, your Cories will have their sandy beach to play, sift for food and to rest upon without having to break down the entire aquarium or remove everything first. Once the sand is in place, refill the aquarium as you normally would at a water change.

Time taken is around 30-45 minutes...you can do it on your own but an extra pair of hands is always useful when pouring sand through the bottle. Its very easy, saves alot of time and the Cories will love their new beach area to feed, relax and play.

I did this in two of my tanks, works well!
Only tip I'd add is if possible, once you've pushed back the substrate from the area, use hardscape like rocks, riverstones, something like that to hold back the gravel, if possible. Then add the sand. Because otherwise the sand and gravel wind up mingling together, especially with active substrate fish like cories. One of my tanks has this and is super easy to maintain. One doesn't, and I constantly have to use a sieve like scoop I have to sift gravel out of the sand and put it towards the back again. Gravel would cover the sand in time otherwise.

 

[VioletThePurple]

I was directing my comments as much if not more at some other members in this thread too, just so you know it was not a hammering on you.

I doubt starvation was the issue, and obviously any hungry fish will poke into the substrate for food. But with gravel it is physically impossible for these fish to filter feed, and that is an instinct in their genetics that must be provided for if the fish are to be in good health. About 90-95% of all diseases we encounter in aquarium fish are due to stress. The pathogen/parasite or whatever may be present, but fish that are not under stress will in the majority of cases fight it off. Fish in the habitat would have disappeared long ago if this ability was not the case. So, avoiding stress is clearly the only good road to healthy fish. Stress weakens fish, slowly usually, and there are no visible (to the aquarist) signs until it has almost too late, and in some cases even then it is not obvious...the aquarist says, "my fish just suddenly died, why?" but most of the time the underlying reason causing stress becomes apparent. Stress is caused by any un-natural condition. This is why we continually advise that one must research the habitat conditions so we can provide as close as possible. Only by giving the fish what they "expect" can we be reasonably certain they will be "fine." We cannot talk to them to find out how they feel, and visible signs of trouble are often unobserved or may not even be visible.

Replacing the substrate can be safely done, I did it many years ago after I learned the benefits of sand. Your fish numbers seem to be few now, so it would not be too onerous. I won't go into all that, but if you intend cories you need sand, plainly stated. I could see the difference in my 60+ cories when I did this, on the advice of Heiko Bleher. We all learn throughout our time in this hobby.

Oh, so the cories were probably stressed out from not being able to filter feed as they naturally would, stress led to disease and since they're stressed, they're less likely to fight it off. Thanks for the explanation. I realize how important sand is now.

 

[Byron]

Oh, so the cories were probably stressed out from not being able to filter feed as they naturally would, stress led to disease and since they're stressed, they're less likely to fight it off. Thanks for the explanation. I realize how important sand is now.

Many things we consider harmful because each contributes to stress, or to somehow weakening the fish. I still think it is likely a bacterial issue here, but stress is still a factor in weakening the fish. As are the nitrates at 20 ppm. No tropical fish species we maintain in our tanks lives in water in the habitat with nitrates present, or if they are, they are so low they can scarcely be measured. We know nitrate slowly weakens fish in various ways, again making them more susceptible to disease or other problems. It is a cumulative effect of stress, nitrates, frustration at feeding limits, etc, etc, ...etc. That weakens, but the immediate cause may have been/be bacterial.

 

[VioletThePurple]

Update: Corydoras now have a sand play place.

I don't know if I have enough sand to cover everything, I still have more to add and I'm taking a break right now. I'll probably throw out the gravel I had to move. I'm trying to move the gravel on the other side of the decor. There's sand floating at the top but hopefully it'll go away in time.

 

[Greenhatgofish45]

Yes, it's all in the same tank. I only have one main tank. I know it's a little low, I've been trying to boost it with partial daily water changes. Also those results are old, it's been about a week since I tested so they may not be accurate.

Have you considered focusing on a planted tank for a while (months) then.adding one or two fish at a time. Planted tanks seem.wY more forgiving