Help! I'm Overstocked!!
There is often a time when you look at your tank and realise it's become overstocked. Perhaps you didn't realise before now; the pet store told you it was fine! Perhaps you've stocked using minimum guidelines, but now your fish have grown - they're looking cramped. Perhaps your big tank broke and you had no option but to move the fish to a smaller tank. There are many reasons why people overstock tanks, but it all comes down to the same issue - too many fish, too little space.
What is overstocked?
MINIMUM guidelines for fancy Goldfish - 20gallons for the first and 15 gallons for each thereafter.
MINIMUM guidelines for single tailed Goldfish - 30 gallons per fish.
If you fall beneath these guidelines, you are overstocked.
Bear in mind; larger fish may need more space than those guidelines. A fully grown single tailed Goldfish will need 6'×2'×2' in order to be able to swim, move and be happy (not per fish, but they will require that kind of room to be able to move) - so think of minimum guidelines as just that - guidelines.
Just because your tank isn't overstocked by these numbers, doesn't mean it isn't overstocked. They are there to let us know what is the absolute smallest we can possibly go, not what the best size for our fish is.
When I look at my Usagi, there isn't a chance he'd be happy in a 20G, he's just too big - if I put him in a 20G, it would be overstocked. Using your initiative is also part of deciding wether or not you are overstocked.
MINIMUM guidelines for single tailed Goldfish - 30 gallons per fish.
If you fall beneath these guidelines, you are overstocked.
Bear in mind; larger fish may need more space than those guidelines. A fully grown single tailed Goldfish will need 6'×2'×2' in order to be able to swim, move and be happy (not per fish, but they will require that kind of room to be able to move) - so think of minimum guidelines as just that - guidelines.
Just because your tank isn't overstocked by these numbers, doesn't mean it isn't overstocked. They are there to let us know what is the absolute smallest we can possibly go, not what the best size for our fish is.
When I look at my Usagi, there isn't a chance he'd be happy in a 20G, he's just too big - if I put him in a 20G, it would be overstocked. Using your initiative is also part of deciding wether or not you are overstocked.
What's so bad about being Overstocked?
Over stocking has many implications. It is vital to the health and well being of your fish that this issue is fixed as soon as possible. Whilst overstocked, your fish are in danger. They may be fine right now, but it doesn't take long for things to spiral out of control.
Water Quality
In an overstocked tank, good water quality can be nigh on impossible to maintain. Less water to dilute waste means water quality is poor in an overstocked aquarium.
Poor water quality is the number one cause of illness and disease in fish. Keep your water good and the rest will follow. It is often said that we keep water, the water keeps the fish - this couldn't be more accurate.
Toxins build up very quickly in an overstocked tank; not jusy those we test for (ammonia, nitrite and nitrate) but other nasties too. Even if your water results read fine, it's unlikely your water is good quality. Just because you aren't testing for dissolved organic compounds and hormones, doesn't mean they don't exist. For this reason, regardless of you test results, water changes are paramount. 50% every other day is the least you can give your babies, to give then a happy life.
In am overstocked aquarium, the fish will also use up the electrolytes and minerals in the water faster than they would in an appropriately stocked tank, this can also cause health issues and is another reason water quality can be difficult to maintain.
Temperature and pH swings are also common in small tanks, these can cause extreme stress for the fish and even cause fatalities.
Remember, we keep water - the water keeps the fish.
Stunting
It is a common misconception that a Goldfish will only grow as big as the tank it's in. The only way this is true is on the outside. Keep your fish in too small a tank, and it won't grow. Why? It doesn't have the space to. Growth hormones will build up and cause stunting.
The internal organs of the Goldfish will continue to grow, even though the outside stays small. At the very least, this is a sad existence. More often than not, it leads to a very slow and painful death.
Illness
As I've already said, in an overstocked tank -illness is rife. Poor water quality is the number one cause of sickness; fin rot, fungus, swim bladder disorder, dropsy, ammonia poisoning, nitrite poisoning, nitrate poisoning and oxygen deprivation are just a few things that can be caused by poor water quality (there are other causes too, but water quality is a biggie!)
Aggression
Ever shared a room with a sibling? It's a bleeding nightmare! No escape from their whining, no time for yourself, no peace and quiet.
Yep! Goldfish feel exactly the same. On top of that - they can't leave their room when their sister is driving them nuts (Love you sis!)... and their sibling is pooping all over them, all the time!!
Aggression is a common problem in overstocked tanks as the fish themselves may even try to cut numbers in the tank to make the environment more stable for themselves. They may pick on the weaker fish in order to give themselves the room they need - or just because it's flipping annoying having too little room!
Water Quality
In an overstocked tank, good water quality can be nigh on impossible to maintain. Less water to dilute waste means water quality is poor in an overstocked aquarium.
Poor water quality is the number one cause of illness and disease in fish. Keep your water good and the rest will follow. It is often said that we keep water, the water keeps the fish - this couldn't be more accurate.
Toxins build up very quickly in an overstocked tank; not jusy those we test for (ammonia, nitrite and nitrate) but other nasties too. Even if your water results read fine, it's unlikely your water is good quality. Just because you aren't testing for dissolved organic compounds and hormones, doesn't mean they don't exist. For this reason, regardless of you test results, water changes are paramount. 50% every other day is the least you can give your babies, to give then a happy life.
In am overstocked aquarium, the fish will also use up the electrolytes and minerals in the water faster than they would in an appropriately stocked tank, this can also cause health issues and is another reason water quality can be difficult to maintain.
Temperature and pH swings are also common in small tanks, these can cause extreme stress for the fish and even cause fatalities.
Remember, we keep water - the water keeps the fish.
Stunting
It is a common misconception that a Goldfish will only grow as big as the tank it's in. The only way this is true is on the outside. Keep your fish in too small a tank, and it won't grow. Why? It doesn't have the space to. Growth hormones will build up and cause stunting.
The internal organs of the Goldfish will continue to grow, even though the outside stays small. At the very least, this is a sad existence. More often than not, it leads to a very slow and painful death.
Illness
As I've already said, in an overstocked tank -illness is rife. Poor water quality is the number one cause of sickness; fin rot, fungus, swim bladder disorder, dropsy, ammonia poisoning, nitrite poisoning, nitrate poisoning and oxygen deprivation are just a few things that can be caused by poor water quality (there are other causes too, but water quality is a biggie!)
Aggression
Ever shared a room with a sibling? It's a bleeding nightmare! No escape from their whining, no time for yourself, no peace and quiet.
Yep! Goldfish feel exactly the same. On top of that - they can't leave their room when their sister is driving them nuts (Love you sis!)... and their sibling is pooping all over them, all the time!!
Aggression is a common problem in overstocked tanks as the fish themselves may even try to cut numbers in the tank to make the environment more stable for themselves. They may pick on the weaker fish in order to give themselves the room they need - or just because it's flipping annoying having too little room!
What do I do now?
Of course, you will need to upgrade as soon as is possible but in the mean time water changes are key.
If your tank is under 80L/20G and has more than one fish, you will need to be doing 50% water changes at a minimum of every other day, preferably every day.
If you have a bowl or something that would be considered extremely small (to me, under 40litres/10G), then you would be best doing multiple 50% water changes daily and getting you fish into something bigger is a matter of absolute urgency.
If you are severely overstocked, daily 50% water changes will be needed. Twice would be better.
Just because your tank is big, doesn't mean it isn't overstocked. If you have more fish than you should in your tank, water changes 3-4 times a week should be as standard. It may be necessary to perform changes daily.
Don't forget, it's not just about Ammonia, Nitrite and Nitrate - they're just what we monitor. Dissolved organic compounds, hormones and other waste needs removing and electrolytes and minerals need replacing. Just because you have 0ppm Ammonia, 0ppm Nitrite and 0ppm Nitrate does not mean your water is good quality. It's a fair sign, but it isn't everything. If I don't test for nitrates, it doesn't mean they aren't there - just that I haven't tested for them. It's the same for other things present in the water.
Clear water doesn't mean clean water. If your tank is overstocked - water change, water change, water change.
You will need to get your fish into something bigger ASAP. It doesn't need to be a glass aquarium, but it needs to gold more water than you currently have - or be something you can divide fish up and spread them evenly between more water vessels.
Nitrifying bacteria is present on all surfaces in the aquarium. The vast majority live in the filter. Anything you put in the tank; substrate, rocks, wood, decor, anything you add takes away water volume. If you are overstocked, remove these items and watch your parameters closely.
Though you will be doing water changes very regularly, you should still watch out for cycle bumps. If you have a bump, perform MORE water changes -do not follow the fish in cycle guide. It will take longer to get back on track, but as we don't have the water volume to dilute all waste; water changes are key. We aren't testing for everything that can harm our fish and in overstocked tanks, these build up quickly. More water changes protect the fish; yes, it's a pain - but not worth losing fish over.
Prime, Prime, Prime! This will protect your fish from ammonia and nitrite for 24hours - but not everything. Whilst it will protect them from many harmful toxins, it doesn't cover everything. Prime and water changes go hand in hand.
If your tank is under 80L/20G and has more than one fish, you will need to be doing 50% water changes at a minimum of every other day, preferably every day.
If you have a bowl or something that would be considered extremely small (to me, under 40litres/10G), then you would be best doing multiple 50% water changes daily and getting you fish into something bigger is a matter of absolute urgency.
If you are severely overstocked, daily 50% water changes will be needed. Twice would be better.
Just because your tank is big, doesn't mean it isn't overstocked. If you have more fish than you should in your tank, water changes 3-4 times a week should be as standard. It may be necessary to perform changes daily.
Don't forget, it's not just about Ammonia, Nitrite and Nitrate - they're just what we monitor. Dissolved organic compounds, hormones and other waste needs removing and electrolytes and minerals need replacing. Just because you have 0ppm Ammonia, 0ppm Nitrite and 0ppm Nitrate does not mean your water is good quality. It's a fair sign, but it isn't everything. If I don't test for nitrates, it doesn't mean they aren't there - just that I haven't tested for them. It's the same for other things present in the water.
Clear water doesn't mean clean water. If your tank is overstocked - water change, water change, water change.
You will need to get your fish into something bigger ASAP. It doesn't need to be a glass aquarium, but it needs to gold more water than you currently have - or be something you can divide fish up and spread them evenly between more water vessels.
Nitrifying bacteria is present on all surfaces in the aquarium. The vast majority live in the filter. Anything you put in the tank; substrate, rocks, wood, decor, anything you add takes away water volume. If you are overstocked, remove these items and watch your parameters closely.
Though you will be doing water changes very regularly, you should still watch out for cycle bumps. If you have a bump, perform MORE water changes -do not follow the fish in cycle guide. It will take longer to get back on track, but as we don't have the water volume to dilute all waste; water changes are key. We aren't testing for everything that can harm our fish and in overstocked tanks, these build up quickly. More water changes protect the fish; yes, it's a pain - but not worth losing fish over.
Prime, Prime, Prime! This will protect your fish from ammonia and nitrite for 24hours - but not everything. Whilst it will protect them from many harmful toxins, it doesn't cover everything. Prime and water changes go hand in hand.
I can't afford a glass tank right now...
Our Budget Busting guide has many tips on how to cheaply upgrade and fish keep on a budget - I recommend reading this guide as it's full of tips and tricks.
Food grade plastic tubs, kiddie pools, preformed ponds, storage totes - all sorts can be used to house fish. It might not be as pretty as a glass tank - but there is nothing more unattractive than a tank of sick fish, so don't let yourself be fooled by aesthetics. Remember, these are living beings - not decorative items.
Food grade plastic tubs, kiddie pools, preformed ponds, storage totes - all sorts can be used to house fish. It might not be as pretty as a glass tank - but there is nothing more unattractive than a tank of sick fish, so don't let yourself be fooled by aesthetics. Remember, these are living beings - not decorative items.
I can't upgrade. Ever. What now?
Sometimes, we can't upgrade - landlords may not let us, our house may not support the weight of a larger tank, we may not be allowed more tanks, we may have dived into this without realising the kind of space we need and we literally don't have the space, money and time to devote to the hobby.
Unfortunately, if your tank is severely overstocked and there's no chance you can upgrade in the near future, the best thing to do is rehome the fish. Whilst it hurts to consider rehoming beloved pets, it hurts a hell of a lot more to lose them - especially when it could have been avoided. The fish doesn't need to suffer and at the very least, you don't need the guilt.
You can't just keep your fish in their overstocked tank long term, because you don't want to rehome them as it will cause them to suffer and that is wholly unfair on them. Water changes may keep the water clean, but you have to consider their quality of life too; no room to swim and grow isn't the life of a happy fish.
Keeping your fish overstocked for long periods of time will have a detrimental effect on their health - it can be fatal.
As a fishkeeper, your aim should be to provide your fish with the absolute best care. You should put their needs above your own. If you can't provide them with what they need - the fish should be rehomed to someone that can provide them with that.
I know, you love your Goldfish but think about them; should your enjoyment come above their wellbeing? Should your emotions come before their health? For me, absolutely not. These are living beings who deserve to be treated with the same respect as every other living being. If your neighbour left their dog in a crate for weeks at a time, let them foul themselves, didn't clean up after them, jut threw then some food every now and then - you would have something to say about it. Rightly so! It's animal abuse. So why should animal fish be any different?
Unconditional love is doing what's right by those you love, even if it hurts you. I know it's hard, believe me. No one ever wants to rehome their pets. It's heartbreaking, but it's the right thing to do. You will feel better in time and you can trust that your fish will be happier and healthier in an appropriate environment. That's love.
These are pets, animals, living beings - not decorative items. If you're after a beautiful tank and don't want/can't manage maintenance or an upgrade, then rehome the Goldfish and plant your tank - shrimp have a very low bioload so you'd only need minimal weekly water changes. Whatever you do stock is a living being and shoukd be treated with the same respect as any other living being. If you can't/don't want maintenance but want a tank - don't add any livestock, stick with plants. Though they will still need some care, it won't be as much as if you add livestock. It will still be beautiful, but no living being will have to suffer.
No one can force you to rehome them, but you have to look at the bigger picture. No one will judge you for rehoming a fish - in fact, many will praise you for doing something so hard because you know it was the right thing to do. Do not be ashamed, take pride in your decision.
When you have the time, space and finances - you can get back into it!
Unfortunately, if your tank is severely overstocked and there's no chance you can upgrade in the near future, the best thing to do is rehome the fish. Whilst it hurts to consider rehoming beloved pets, it hurts a hell of a lot more to lose them - especially when it could have been avoided. The fish doesn't need to suffer and at the very least, you don't need the guilt.
You can't just keep your fish in their overstocked tank long term, because you don't want to rehome them as it will cause them to suffer and that is wholly unfair on them. Water changes may keep the water clean, but you have to consider their quality of life too; no room to swim and grow isn't the life of a happy fish.
Keeping your fish overstocked for long periods of time will have a detrimental effect on their health - it can be fatal.
As a fishkeeper, your aim should be to provide your fish with the absolute best care. You should put their needs above your own. If you can't provide them with what they need - the fish should be rehomed to someone that can provide them with that.
I know, you love your Goldfish but think about them; should your enjoyment come above their wellbeing? Should your emotions come before their health? For me, absolutely not. These are living beings who deserve to be treated with the same respect as every other living being. If your neighbour left their dog in a crate for weeks at a time, let them foul themselves, didn't clean up after them, jut threw then some food every now and then - you would have something to say about it. Rightly so! It's animal abuse. So why should animal fish be any different?
Unconditional love is doing what's right by those you love, even if it hurts you. I know it's hard, believe me. No one ever wants to rehome their pets. It's heartbreaking, but it's the right thing to do. You will feel better in time and you can trust that your fish will be happier and healthier in an appropriate environment. That's love.
These are pets, animals, living beings - not decorative items. If you're after a beautiful tank and don't want/can't manage maintenance or an upgrade, then rehome the Goldfish and plant your tank - shrimp have a very low bioload so you'd only need minimal weekly water changes. Whatever you do stock is a living being and shoukd be treated with the same respect as any other living being. If you can't/don't want maintenance but want a tank - don't add any livestock, stick with plants. Though they will still need some care, it won't be as much as if you add livestock. It will still be beautiful, but no living being will have to suffer.
No one can force you to rehome them, but you have to look at the bigger picture. No one will judge you for rehoming a fish - in fact, many will praise you for doing something so hard because you know it was the right thing to do. Do not be ashamed, take pride in your decision.
When you have the time, space and finances - you can get back into it!
Once you have the information you need in order to care for Goldfish appropriately, it is YOUR RESPONSIBILITY TO do the right thing. No one can force you to do anything, but these fish are relying on YOU to give them the life they deserve.
Pet stores are there to make money. Whilst this doesn't mean they are alway wrong, take their advice with a pinch of salt and do your own research.
Many have been "fooled" by incorrect advice and that's fine - it's fixable. Not acting is where the issue lies. No one will judge you for following bad advice; but bow you have the information you need it's down to you to fix it.
You will be rewarded with happy, healthy fish - nothing is more joyous in this hobby than that.
Your fish may have survived thus far, but have they thrived?
Pet stores are there to make money. Whilst this doesn't mean they are alway wrong, take their advice with a pinch of salt and do your own research.
Many have been "fooled" by incorrect advice and that's fine - it's fixable. Not acting is where the issue lies. No one will judge you for following bad advice; but bow you have the information you need it's down to you to fix it.
You will be rewarded with happy, healthy fish - nothing is more joyous in this hobby than that.
Your fish may have survived thus far, but have they thrived?