New 20 gallon tank with rescued goldfish

[Libby1]

My daughter opened a 20 gallon tank, added a few plants, and has been wanting to add fish but waited for it to cycle and once it cycled, before she had the chance to go to the store to buy fish, she came upon an abanadoned little gold fish left on the street in a tiny container with barely a drop of water. (people are horrible!!!!!) So she rescued it and it's SUPER happily swimming around in a 20-gallon all on its own!

However..... my daughter really wanted to get a mix of fish, for instance 2 of a kind of multiple species or something like that. I was going to ask you what your suggestions are, but now we are stuck with the problem of this goldfish; from what I understand, they like colder water and tropical fish need warmer water. Also, they get the tank so dirty. And they grow big. Etc. We are trying to find someone who would take the rescue (although it's a shame not to be able to keep him) but haven't had success yet. Any suggestions or thoughts?? Is there a possiblity to yes keep that fish, and somehow get him acclimated to warmer water....? Or is that insane to think of? Is it even possible for him to get along with other fish?

And on that note, what types of fish would you say get along with one another as a mix of fish in a 20-gallon aquarium?

We love tiger barbs but upon researching it seems they are pretty aggressive fish.. my daughter wants a peaceful tank. I told her I'm going to consult the experts because unfortunately I've learned the hard way by trusting LFS....... She's hoping to go to the store tomorrow to take a look and would love to bring home fish but obviously wants to do it right which is why I'm asking you all these questions.

Looking forward to hear back from you. I really hope there's a way to perhaps be able to keep that goldfish; he's still quite little... but obviously you're the one who'd know, so I'm looking forward to hear back from you. I was very proud to tell my daughter the whole "being afraid diagnosis" regarding my parrot! She's like, "Huh? That fish you thought was dying was simply afraid??" Lol

 

[fishkeeper123]

My daughter opened a 20 gallon tank, added a few plants, and has been wanting to add fish but waited for it to cycle and once it cycled, before she had the chance to go to the store to buy fish, she came upon an abanadoned little gold fish left on the street in a tiny container with barely a drop of water. (people are horrible!!!!!) So she rescued it and it's SUPER happily swimming around in a 20-gallon all on its own!

However..... my daughter really wanted to get a mix of fish, for instance 2 of a kind of multiple species or something like that. I was going to ask you what your suggestions are, but now we are stuck with the problem of this goldfish; from what I understand, they like colder water and tropical fish need warmer water. Also, they get the tank so dirty. And they grow big. Etc. We are trying to find someone who would take the rescue (although it's a shame not to be able to keep him) but haven't had success yet. Any suggestions or thoughts?? Is there a possiblity to yes keep that fish, and somehow get him acclimated to warmer water....? Or is that insane to think of? Is it even possible for him to get along with other fish?

And on that note, what types of fish would you say get along with one another as a mix of fish in a 20-gallon aquarium?

We love tiger barbs but upon researching it seems they are pretty aggressive fish.. my daughter wants a peaceful tank. I told her I'm going to consult the experts because unfortunately I've learned the hard way by trusting LFS....... She's hoping to go to the store tomorrow to take a look and would love to bring home fish but obviously wants to do it right which is why I'm asking you all these questions.

Looking forward to hear back from you. I really hope there's a way to perhaps be able to keep that goldfish; he's still quite little... but obviously you're the one who'd know, so I'm looking forward to hear back from you. I was very proud to tell my daughter the whole "being afraid diagnosis" regarding my parrot! She's like, "Huh? That fish you thought was dying was simply afraid??" Lol

First thing is, well done for rescuing the gold fish. However, as you said they are messy and do need cold temperatures. Keeping a single goldfish in a 20 gallon is possible with no other tank mates. However it requires large water changes regularly. You could go down that route if you wanted however I think getting tropical fish is going to be easier for your daughter on maintananfe and she will be able to get multiple species of fish. What fish you get is your choice. Not tiger barbs for a 20 gallon tho but you could probably get 3 species in there happily. A good fish combo I’ve had are a single Bolivian ram + shoaling fish and maybe cories as well. I like my leopard danios however you could choose many other different types of shoaling fish. I would choose one suitable sized fish and then it’s easier to base the stocking of that.

 

[Aiken Drum]

While it's great your daughter rescued the goldfish, 20 gallons is on the small size.

If its a comet/ common type goldfish it's really better off in a pond, but a 50g would provide some quality of life. 20g is better than it's prospects before you rescued it though, so that has to be take into consideration. You might rehome it, but whoever took it may not give it a better living environment than the 20g.

If it's a fancy type goldfish then 20g is at the minimum end of things. It would be able to live in there, enjoy some quality of life, certainly better than the tiny container, but would do better in something a little bit bigger. I probably wouldnt put money into an upgrade, but certainly wouldn't add anything else into the aquarium.

For context though, the world record longest lived goldfish was 43 years, and it lived in a bowl that was probably about 5g, and it's tankmate lived to 19 years. So if you are diligent with water changes, and win the lottery with regards to fish genetics, goldfish can live in small environments. But its the exception rather than the rule.

So you really need to decide whether the 20g is a permanent home for your goldfish or if you want to rehome it and go with a tropical community.

As for keeping a community, most community fish are social and need to be kept in groups of their own species. So 2 individuals of numerous species isn't a good idea. In 20g you are probably better off looking at 3 groups of small species, each group with 6 fish.

Or, if you live in a country where glofish are legal, maybe a mix of all the colour varients of one of their species will give you that variety you are looking for. A 20 gallon aquarium with 15 to 20 glotetras all different colours might be just what you are looking for.

Tiger barbs can be aggressive, but if the school is big enough it isn't usually a problem. Tiger barbs also come in different colour varients, there are standard ones, green, albino, gold. Maybe 10 to 12 tiger barbs with a mix of different colour varients would fit the bill. 20g is a bit small for Tiger barbs though.

 

[Andy Sager]

Read Aiken's answer. You don't get goldfish to adapt to warmer water. You kill the goldfish a little faster when you keep goldfish in warmer water. It's a bad idea. Plus keeping that kind of fish in such a small tank is also no help. You are exactly in the same situation as the parrot in that small tank. It's a ticking time bomb. As for what fish to mix with him, nothing that grows to any kind of larger size. You are very limited by the types of species that like cooler water. If you want to teach your Daughter good husbandry and proper pet keeping, teach her that she can't have everything she wants or the way she wants them as not everything in the animal world gets along together and not everything gets along as a single male & female or alone when they need larger schools. She can have a nice collection of smaller species OR she can have the goldfish. She shouldn't have both.
I'm currently on the road so I don't have access to the internet everywhere I'm going so I'm also not going to respond immediately but will when I get service.

 

[Libby1]

Hi, all! First, thanks for all your detailed responses. I will mention again that although I often don't get to respond right away, it's not because I didn't read your message or don't feel it's important to reply; it's just because in a rush I quickly read the information I need in order to get to what I have to do, and respond later if I don't have the moment to respond right on the spot. But you're not responding for nothing! So thank you.

Secondly, @Andy Sager I was actually getting a bit concerned when I saw you're not responding because you do usually respond fairly promptly! Gald you're okay, and safe travels!

That being said, I will update you all and I really hope I can gain a bit of clarity.

First, she still has the goldfish and it's doing fine (below I will detail the situation now and that's where he's in) but based on what you're saying about it not being a good idea to pair him with tropical fish, and in a 20-gal, etc I believe my daughter would look for a home for him. I will suggest to her that she does that. But at least for now she didn't have to put him in a bucket.

But here's what's been happening since I read your responses:

Indeed, on Friday afternoon she went to the fish store (I went with her). She ended up buying:

6 Neon tetras
3 paint tetras
3 Glow tetras
1 Albino pleco
2 Catfish

They were doing perfectly fine until last night (Saturday night) where she noticed one of the neon tetras breathing fast and being a bit listless. The same happened to another one, so she removed both and put them in a small bucket..

I came over to test her water: 0 ammonia, 0 nitrite, 6.6 PH, approx 25 Nitrate. I told her to do a 25% water change. That was approximately 1:30am. The fish all got very lively. However I did notice that one of the catfish was breathing heavily.

This morning, she noticed the catfish was breathing heavily and not moving. So - without asking me (brilliant) - she did another water change. Yikes. As of now (Sunday, 3:00pm) all fish seem to be fine, except yet another neon tetra, and the catfish is still breathing heavily. I told her not to do anymore water changes for now, and I will test her water later.

A bit of history about this tank, so we could figure out if this is new tank syndrome or something, and hopefully you could help me do the right thing so it cycles properly.....

A while ago she went to the pet store (she had to do it all "on her own" of course, till she realized Mommy might know a small thing or two)... Lol. I love her. Just commenting on the "why's".
Anyway, the LFS guy coaxed her into buying a few plants (she wanted planted tank) and some weird kind of black substrate; it's supposedly very natural and great for plants and never has to be suctioned (according to what he said). I could find out the name of that stuff, if you don't know what I'm talking about, because I would actually really want to hear your thoughts on that. Basically, the LFS had told her that the tank will cycle itself automatically while the plants are in there with the black stuff. Maybe they told her to add stability, but nothing about adding food or anything else. Which seems very odd to me. They said after 2 weeks she can add fish.

She didn't get to add fish at that point, and the black substrate made her water all black, drove her nuts any time she wanted to adjust a plant because the water got black all over again, so she decided to buy little gravel style rocks and put that instead. Rinsed out the entire tank, put the rocks in, put the plants back. The filter she has is now the same one as I have in my little tank and it's been maintaining the situation so I'm guessing it's a good choice for filter (unless you suggest otherwise. I can post a link here if you wanna see it).

Then, approximately a week or so ago (maybe 2 weeks) she found the little goldfish and rescued it. So it's been in the tank, pooping, eating, etc. Which I'm guessing started the proper cycling... correct? He's been doing mighty fine and is a feisty little fish.

Then on friday, is when she added all the new fish, and the above started happening (the neon plecos getting sick or rather, breathing fast, laying on the side, etc) and the catfish breathing fast.

Oh, just to mention, she hadn't had a heater in there and the water temp was approx 70 so she got a heater and it's now at approx 75. Interestingly, it doesn't seem to affect the goldfish at all.

But why have her fish been getting sick (and maybe those 3 died.... I don't know at this point. If not, can they be saved..???) Do you know what might be going on...??? Are the neon plecos more of a delicate species and perhaps the higher nitrates harmed them, but the water changes will help the rest of the fish survive and be fine...? Is this part of the cycling of the tank? Because obviously we don't really know the status of bacteria growth in the tank. She did suction the gravel during the water changes; did she do the right thing?

I would love to hear your input so she does not lose more fish. She's really trying so hard to do the right thing. And I wanna give her the right advice. And by the way she says thanks!!! And I do as well.

 

[fishkeeper123]

Hi, all! First, thanks for all your detailed responses. I will mention again that although I often don't get to respond right away, it's not because I didn't read your message or don't feel it's important to reply; it's just because in a rush I quickly read the information I need in order to get to what I have to do, and respond later if I don't have the moment to respond right on the spot. But you're not responding for nothing! So thank you.

Secondly, @Andy Sager I was actually getting a bit concerned when I saw you're not responding because you do usually respond fairly promptly! Gald you're okay, and safe travels!

That being said, I will update you all and I really hope I can gain a bit of clarity.

First, she still has the goldfish and it's doing fine (below I will detail the situation now and that's where he's in) but based on what you're saying about it not being a good idea to pair him with tropical fish, and in a 20-gal, etc I believe my daughter would look for a home for him. I will suggest to her that she does that. But at least for now she didn't have to put him in a bucket.

But here's what's been happening since I read your responses:

Indeed, on Friday afternoon she went to the fish store (I went with her). She ended up buying:

6 Neon tetras
3 paint tetras
3 Glow tetras
1 Albino pleco
2 Catfish

They were doing perfectly fine until last night (Saturday night) where she noticed one of the neon tetras breathing fast and being a bit listless. The same happened to another one, so she removed both and put them in a small bucket..

I came over to test her water: 0 ammonia, 0 nitrite, 6.6 PH, approx 25 Nitrate. I told her to do a 25% water change. That was approximately 1:30am. The fish all got very lively. However I did notice that one of the catfish was breathing heavily.

This morning, she noticed the catfish was breathing heavily and not moving. So - without asking me (brilliant) - she did another water change. Yikes. As of now (Sunday, 3:00pm) all fish seem to be fine, except yet another neon tetra, and the catfish is still breathing heavily. I told her not to do anymore water changes for now, and I will test her water later.

A bit of history about this tank, so we could figure out if this is new tank syndrome or something, and hopefully you could help me do the right thing so it cycles properly.....

A while ago she went to the pet store (she had to do it all "on her own" of course, till she realized Mommy might know a small thing or two)... Lol. I love her. Just commenting on the "why's".
Anyway, the LFS guy coaxed her into buying a few plants (she wanted planted tank) and some weird kind of black substrate; it's supposedly very natural and great for plants and never has to be suctioned (according to what he said). I could find out the name of that stuff, if you don't know what I'm talking about, because I would actually really want to hear your thoughts on that. Basically, the LFS had told her that the tank will cycle itself automatically while the plants are in there with the black stuff. Maybe they told her to add stability, but nothing about adding food or anything else. Which seems very odd to me. They said after 2 weeks she can add fish.

She didn't get to add fish at that point, and the black substrate made her water all black, drove her nuts any time she wanted to adjust a plant because the water got black all over again, so she decided to buy little gravel style rocks and put that instead. Rinsed out the entire tank, put the rocks in, put the plants back. The filter she has is now the same one as I have in my little tank and it's been maintaining the situation so I'm guessing it's a good choice for filter (unless you suggest otherwise. I can post a link here if you wanna see it).

Then, approximately a week or so ago (maybe 2 weeks) she found the little goldfish and rescued it. So it's been in the tank, pooping, eating, etc. Which I'm guessing started the proper cycling... correct? He's been doing mighty fine and is a feisty little fish.

Then on friday, is when she added all the new fish, and the above started happening (the neon plecos getting sick or rather, breathing fast, laying on the side, etc) and the catfish breathing fast.

Oh, just to mention, she hadn't had a heater in there and the water temp was approx 70 so she got a heater and it's now at approx 75. Interestingly, it doesn't seem to affect the goldfish at all.

But why have her fish been getting sick (and maybe those 3 died.... I don't know at this point. If not, can they be saved..???) Do you know what might be going on...??? Are the neon plecos more of a delicate species and perhaps the higher nitrates harmed them, but the water changes will help the rest of the fish survive and be fine...? Is this part of the cycling of the tank? Because obviously we don't really know the status of bacteria growth in the tank. She did suction the gravel during the water changes; did she do the right thing?

I would love to hear your input so she does not lose more fish. She's really trying so hard to do the right thing. And I wanna give her the right advice. And by the way she says thanks!!! And I do as well.

What are all the fish. Is the albino pleco a Bristlenose? What are the “catfish” corys? They need to be in a larger group if so. Do you know what the paint and tetras are? Skirt tetras? It’s not sounding great but I’m sure the more experienced members will help. I would remove the goldfish sooner rather than later as it will produce lots of waste and so your daughter doesn’t become attached to it. Do you have a decent filter as the catfish and pleco maybe be breathing heavily due to a lack of aeration?

 

[Aiken Drum]

So the goldfish is still in the 20g?

You should really have rehomed the goldfish before getting all the other fish. That was kind of the point of all the above advice. As a next course of action rehome the goldfish. Don't get more fish until the goldfish is removed.

Your water parameters are fine on the face of it, but continue to monitor.

There are issues with the selected fish in that tetras should be kept in groups of at least 6 fish of the same fish. You have 3 glofish tetras which are GM Black skirt tetras, and 3 whatever species a painted tetra is. Painted fish have been painted or injected with dye, but they could have done that to any species. These fish are going to be very stressed and stress will trigger aggession, sickness etc, so thats a potential cause.

How did you acclimate the new fish into the aquarium?

 

[Libby1]

So the goldfish is still in the 20g?

You should really have rehomed the goldfish before getting all the other fish. That was kind of the point of all the above advice. As a next course of action rehome the goldfish. Don't get more fish until the goldfish is removed.

Your water parameters are fine on the face of it, but continue to monitor.

There are issues with the selected fish in that tetras should be kept in groups of at least 6 fish of the same fish. You have 3 glofish tetras which are GM Black skirt tetras, and 3 whatever species a painted tetra is. Painted fish have been painted or injected with dye, but they could have done that to any species. These fish are going to be very stressed and stress will trigger aggession, sickness etc, so thats a potential cause.

How did you acclimate the new fish into the aquarium?

How were the fish painted???!!? I really should post a photo here so you could see the fish I'm talking about. I'll try to do so in a bit. Actually, I'm gonna see if I could find photos on the internet so you get it faster. (update: I'm attaching photos from the internet -- not from her tank -- but this way you see the exact type of fish she has.)

They were acclimated as follows:

Water change done at least half hour before being placed into the new tank. As well as the heater placed in the tank, and the temperature rising to 75 before she added the fish. The bags of fish were floating on top of the water for probably half hour or something like that (I can find out exactly, if you feel that's important info). She then took some tank water and added it to the bags and let that also sit on top of the tank water for a while so they get acclimated. Then she netted them and put them into the main tank without the water in the bag.

The LFS said that 3 of the glowfish and 3 of the painted fish are okay.. If you feel otherwise, I'd like to discuss when and if you feel she should add to those two species. The weird thing is that the neon tetras that did come with 6, they are the sensitive ones that haven't been doing well. Odd.

Yes, the goldfish is still in there simply because I posted here when she had already planned to go to the fish store so she didn't have the time to rehome it yet, and we felt that putting him in a bucket is way more risky for his survival than first leaving him in the tank, watch him, and then figure out what to do.....

 

[Libby1]

What are all the fish. Is the albino pleco a Bristlenose? What are the “catfish” corys? They need to be in a larger group if so. Do you know what the paint and tetras are? Skirt tetras? It’s not sounding great but I’m sure the more experienced members will help. I would remove the goldfish sooner rather than later as it will produce lots of waste and so your daughter doesn’t become attached to it. Do you have a decent filter as the catfish and pleco maybe be breathing heavily due to a lack of aeration?

No, the albino pleco is not a bristlenose, and the catfish are panda corys. I attached photos in my reply to Aiken (taken from the internet, not the actual fish she has in her tank but the exact same type) so you could see the species I'm talking about. Regarding aeration, the filter does release bubbles and I believe it's a sufficient amount and they're not lacking oxygen. Why, though, did you assume that might be the case? Is there something I should check for?

 

[fishkeeper123]

No, the albino pleco is not a bristlenose, and the catfish are panda corys. I attached photos in my reply to Aiken (taken from the internet, not the actual fish she has in her tank but the exact same type) so you could see the species I'm talking about. Regarding aeration, the filter does release bubbles and I believe it's a sufficient amount and they're not lacking oxygen. Why, though, did you assume that might be the case? Is there something I should check for?

Aeration can be a problem, I was just theorising what it could be. What pleco is it then as you can get albino Bristlenoses, the main other albino is the sailfin which get to 12 inches and more. I would get more of the panda cories. I’m so sorry but those painted tetras are disgusting I hate to find out how they are that colour. I would keep the neons, add more cories so you have 6, get more glowfish and rehome those painted things and rehome the goldfish. And the pleco is a maybe due to what species it is. That’s what I would do but the goldfish really does have to go.

 

[Andy Sager]

How were the fish painted???!!?

They are painted Glassfish most likely. Those were the first type of fish I believe to be painted. Unlike the glo-fish, the painted fish do not retain their colors. As the fish grows, the paint fades. IMO, it's a terrible practice and many stores were refusing to carry these fish because of their treatment.

I really should post a photo here so you could see the fish I'm talking about. I'll try to do so in a bit. Actually, I'm gonna see if I could find photos on the internet so you get it faster. (update: I'm attaching photos from the internet -- not from her tank -- but this way you see the exact type of fish she has.)

They were acclimated as follows:

Water change done at least half hour before being placed into the new tank. As well as the heater placed in the tank, and the temperature rising to 75 before she added the fish. The bags of fish were floating on top of the water for probably half hour or something like that (I can find out exactly, if you feel that's important info). She then took some tank water and added it to the bags and let that also sit on top of the tank water for a while so they get acclimated. Then she netted them and put them into the main tank without the water in the bag.

The LFS said that 3 of the glowfish and 3 of the painted fish are okay.. If you feel otherwise, I'd like to discuss when and if you feel she should add to those two species. The weird thing is that the neon tetras that did come with 6, they are the sensitive ones that haven't been doing well. Odd.

It's not odd at all. It wouldn't matter if you had 100 neons in there because you have fish that are sensitive to poor water quality in with a fish that is nothing more than a crapping machine that shouldn't be in with them. ( It's more than just ammonia, nitrites and nitrates. It's about water quality. Neons need clean water. ) This is most likely the issue since Panda Cories have the ability to get air out of the atmosphere if the water does not contain enough dissolved oxygen. Panda coris are also one of the more fragile species of cory cats. Add to that that the goldfish's waste is at the bottom of the tank and so are the cories. The bottom line is that it's going to be difficult to get a fix on the exact cause of the issue because of the mix of fish you have. This can be a valuable lesson for your Daughter: If you don't do the right thing, you suffer the consequences. In this case, fish not doing well and obviously just changing water isn't going to solve the issue ( whatever it is. )

Yes, the goldfish is still in there simply because I posted here when she had already planned to go to the fish store so she didn't have the time to rehome it yet, and we felt that putting him in a bucket is way more risky for his survival than first leaving him in the tank, watch him, and then figure out what to do.....

Have you ever heard the expression " Speed kills"? Well, that's what's going to happen if you don't straighten this out. Either she keeps the goldfish or she keeps the tropicals but she shouldn't keep them both in the same tank. PERIOD!!!!! That's just the facts whether she likes it or not. It's her money ( I assume) so if she doesn't want to waste it, she should listen to more qualified people BEFORE doing anything or adding new fish. (IMO)

 

[Aiken Drum]

How were the fish painted???!!?

Fish are "painted" either by physically injecting dye into the fish, or by dipping the fish into a caustic solution to remove its slime coat and then dipping into a dye to give the colour. This process may be repeated several times until it they have taken on enough colouration to sell, and the colouration will be temporary. As far as I can tell "painted tetra" is a trademarked product, so they are produced by a single manufacturer, but I cant find which method they use. Either way there are obvious animal welfare concerns, and if a store is happy to sell you fish produced in such a way they are happy to sell you anything.

GloFish came up on another recent thread.
Glofish where originally developed as means of tracking water pollution. Jellyfish DNA was integrated into zebra danios which caused them to fluoresce in the presence of toxins. The company GloFish was then set up to take this technology and introduce it to the pet trade expanding beyond the original zebra danio species.

For info, as GloFish are GM fish, in most of the western world they are illegal to import, breed, keep etc without a licence, which would only be granted for scientific purposes. Potentially here in the UK you could face a custodial sentence, although a fine would be more likely.

The LFS said that 3 of the glowfish and 3 of the painted fish are okay.. If you feel otherwise, I'd like to discuss when and if you feel she should add to those two species.

The employee at the LFS job is to sell you stuff, giving advice is secondary. You have no idea if the advice they give you is good advice, or if they even know more about keeping fish than you do. Many store employees are specifically instructed to give advice that leads to a sale. They did their job and sold you fish. I personally wouldn't go near any more "painted" tetras. You could eventually add 3 more GloFish tetras to make up 6, and if the painted fish do well, you could look at getting some non painted fish of the same species. The photo you posted off the Internet may not be the same species of fish as yours, as many fish species get painted, but it looks like a glass fish which is a common species to paint as Andy has suggested.

Rehome the goldfish first. Then go a few weeks with no fish losses before considering more fish.

 

[Aiken Drum]

Just to hammer home that the goldfish needs to be rehomed and why.

It's not really a short term issue for the goldfish, but more long term issues for the golfish and both short and long term issues for the tropical fish.

You have set your aquarium temperature for tropical fish. Your goldfish will tolerate this temperature, but at higher temperature the fishes metabolism will increase, they will be more active, eat more and poop more. This will lead to poorer quality water and increased metabolism reduces lifespan. So short term this will effect the other fish in the aquarium and not be good long term for the goldfish.

Your goldfish and tropical fish have different diets. Food for the goldfish won't suit the tropical fish and vice versa. Feeding both types of food might sound it solves both problems, but you have no control which fish eats which food. Goldfish need feeding regularly, 3 or 4 feedings a day. That won't stop your tropical fish trying to eat the same food at every sitting which will lead to overeating and health problems.

If one fish can fit another fishes mouth, it's now considered food. The neon tetras will certainly be small enough to be on the menu, if it's a larger type of goldfish then all your fish are at risk unless they are fast enough swimmers to avoid being eaten. Corys are a particular problem as they have defensive spines in their dorsal fins. In some species these spines carry a mild poison too. It's not uncommon for goldfish to try and eat a cory and the get the spines stuck in their throat. You are then in a position of either watching both fish die, or having to cut out the cory to save the goldfish.