When you have taken the time to do your research on keeping guppies, bought all the necessary equipment, setup your aquarium and finally went to buy your new fish, its really sad when your fish die. In this article we will dive into the possible reasons and will provide you with the solutions.
Problem: Inappropriate Cycling
When you setup a new aquarium, it needs to be cycled. This means that you need to build up bacteria inside your aquarium that will break down toxic substances like ammonia and nitrate into the less harmful substance nitrite.
To know if your aquarium is cycled, you need to test the water. This can be done trough either test strips or a specific water testing set. The 3 values to look at on these tests are ammonia, nitrite and nitrate.
When ammonia and nitrite give readings above 0, but nitrate does read 0, this means your aquarium is not yet cycled and it is probably the ammonia and nitrite that is killing your fish.
Solutions
When your aquarium is not cycled properly, there are a couple of solutions that you can try.
Water changes
Your tap-water should come with 0 ammonia and nitrites, so doing multiple smaller water changes during the day is a way to keep your fish alive. With every water change you will take water with a high number of ammonia and nitrite out of the aquarium and replace it with water that doesn’t have it. This brings the overall readings in the entire water column down.
During this time, when you are still getting ammonia and nitrite readings, it is also wise to feed your fish less. Food that goes uneaten and stays within the aquarium will start to rot and produce ammonia.
Aquarium quick starter solution
There are multiple brands selling quick start nitrifying bacteria solutions. Although we have never used these products ourselves, we have heard people that had good results with them. When buying these, keep the expiration date in mind. The closer the product is to expiring, the less chance you have of actually getting living bacteria from the bottle.
Filter or media from an established tank
When you take filter media or substrate from an already cycled aquarium, you will also transfer the nitrifying bacteria with it. These bacteria will immediately get to work on processing the ammonia and nitrite in your tank. Keep in mind though, that the colony might not be big enough yet to consume all ammonia and nitrite in your tank. So keep an eye out on your water parameters and do small water changes as necessary.
Problem: Male to female ratio
When keeping guppies, you need to keep the male to female ratio in mind. A ratio of 2 to 3 females for every male is optimal.
When the ratio is out of balance, the males will be harassing the females and fight each other over the female attention. This in turn will create a lot of stress which, over time, will lead to deaths.
When you see broken or torn fins on your guppies, it is a strong indicator this has been happening. Another good indicator is when your female guppies are the first ones to die. This will be due to the stress from the males constantly chasing them.
Solution
Depending on the size of your aquarium you will either have to add more females or remove some males by either bringing them to your local fish shop (LFS) or giving them to someone else who can take them.
For more information on the amount of guppies you can keep, see our guppy care guide.
Problem: Wrong tank mates
When you have a community aquarium, it can be that you unfortunately picked the wrong tank mates for your guppies. Cichlids are especially known for being very aggressive fish.
If you see other fish in your aquarium constantly chasing your guppies, or your guppies have damaged fins, scales or tails there is a good chance that fish are not getting along in your aquarium.
Solution
In this case you will have a couple of hard choices to make. First off it is important to separate the fish from each other before anymore deaths occur. Then you will need to choose which species of fish you want to keep and which should go.
Problem: Low oxygen levels
When the water in your tank, and more specifically the surface, does not move, your fish will slowly use up all the oxygen in the aquarium. While this starts to happen, you will see your guppies breath heavily and swim at the surface. This means that they are slowly suffocating.
Solution
Fixing this problem is quite easy. All you need to do is, making sure the water surface is getting agitated. This will allow for oxygen exchange to happen.
You can do this with a hang on the back filter, that drops the water into your aquarium, a simple airstone or sponge filter, with an airpump.
Problem: Weak genetics
Guppies are know for their wide variety of colors and fin types. The downside of this is that, for breeders to continually breed the same type of fish, they often resort to inbreeding, by mating closely related fish. This can severely shorten the lifespan of your guppy and make it more sensitive to diseases as well as deformities, like a bent spine.
Unfortunately guppies being sold in big pet stores are usually of the lowest quality. We have had experiences with guppies from these stores not living longer than 6 months, all due to bad genetics.
Solution
If you don’t own any guppies yet, check with your supplier how the guppies are bred. It is important to cycle the fish to keep enough diversity in the gene pool.
When you already own guppies, and have them in a community tank, make sure to add some new males and sell or give away your old males to make sure new genes enter the pool of your breeding guppies. Do this at least once per year, when roughly three generations have been born.
Problem: Stressed females
Your female guppies can become completely stressed out and die as a result when you don’t have the correct ratio. Male guppies will constantly chase female guppies in their ever lasting quest to reproduce. This constant chasing is what creates the stressful situation, after a prolonged time the females will be worn out. This weakens the fish and makes it susceptible to diseases and possibly death.
Solution
Be sure to maintain a proper ratio between male and female guppies. There should be 2-3 females per male. More females is of course always an option. Adding more live plants or decorations like caves can also help since they will give the females a place to hide and rest up.
Another possibility is to only keep males or females.
Problem: Low pH
When you are a beginning fish keeper, it is always best to keep fish that match the parameters of your tap water. That being said, there are a number of things that can bring the pH in your aquarium down. Guppies, like all live bearers prefer to have more alkaline water, meaning a pH value of 7 or above.
Solution
To prevent your aquarium water from becoming too acidic, meaning it has a pH value below 7, you can add some crushed corals to your filter or aquarium. When the water is acidic, the corals will dissolve, which will increase the pH and keep it stable.
Problem: Incorrect temperature
Guppies are tropical fish and therefor can not survive in cold water. If you don’t have a heater in your aquarium or the heater is placed in a wrong position, it can be that the cold is killing your beloved fish.
When you live in a tropical climate, it can also be that the water in your aquarium will get too hot for the guppies.
Solution
Add a heater to your aquarium. Make sure the heater is strong enough to keep the temperature between 76 to 78°F, 24.5 to 26.5°C. Its best to place your heater near the filter intake or outlet. This ensures that all the water in your aquarium gets heated to the proper temperature.
In case you live in a tropical climate and the temperature rises above ideal for the guppies, you should get a cooler to maintain a proper temperature.
Problem: Not acclimating your guppies
In case you see dead guppies shortly after adding them to your aquarium, you might have made a mistake in acclimating them to your water parameters. By having sudden changes in parameters from the transportation bag to your aquarium, you will stress your guppies and they can even go into shock. This may lead to your new guppies passing away shortly after.
Solution
The minimum you should do to acclimate your fish, is to float the bag for about 15 minutes. This will at least equalize the water temperature in the bag to that of your aquarium.
You can also take it a step further, and choose to drip acclimate your guppies. Do this by take a piece of flexible tubing, for example airline tubing. Start by making a very loose knot in the tubing on one end. Then put the other end into your aquarium and use a clip or something else to make sure it stays in place. The carefully suck on the end with the knot, so that water starts coming into the tube from the aquarium. If you can’t get any water trough, loosen the knot a bit.
Once the water starts flowing, tighten or loosen the knot so that you have approximately one to two drops every second coming trough. Now let this drip until roughly 75% of the water is from your aquarium.
Problem: Overfeeding
Everyone loves feeding their guppies and watching them eat. However, overfeeding them can be very dangerous.
It can be difficult determining how much to feed your guppies. Advice ranges from 3 times per day, to once every two days. It all depends on the amount and type of food you feed your guppies with every feeding. session
In any case it is important to make sure food does not just fall to the bottom of your aquarium and lies there, rotting away. This will create ammonia spikes in the water chemistry which can be deadly to your fish.
Solution
Generally speaking, guppies are top feeders. This means the will swim near the surface of the water in search for food. However, they are also opportunistic eaters and will eat wherever there is food available. Your guppies can also be conditioned by the breeder to eat food at a certain level in the tank. Keeping this in mind, we will provide you with a couple of examples to determine the right amount of food for your guppies.
Lets take tropical fish flakes as an example. When put into the aquarium, the flakes will float for some time until they are soaked and slowly fall to the bottom, or float under the outlet of an HOB (Hang on the Back) filter.
Now that we know how the food behaves when added to the aquarium, we need to decide how often you want to feed your guppies. If you want to feed them every other day, a good approach will be to drop a couple of flakes in your aquarium and have the fish eat them all. Then drop a couple more in and repeat this process until they show no more interest in the food or you have been doing this for a couple of minutes. The more guppies you have, the more flakes you can add every time or the longer you can repeat this process to make sure everyone gets some food.
In case you want to feed your guppies multiple times per day, you should apply the same process, but stop feeding your guppies after a minute or so. This way your guppies will all have had something to eat and will be hungry enough when the next feeding session comes around.
Whatever feeding routine you choose, it is still a good idea to skip one day of every now and then. This allows your guppies to pass all the food and they wont get constipated.
Problem: Overcrowded aquarium
Guppies are know for reproducing very fast. Within a single month, a female guppy can give birth to 20 to 200 guppies. For this reason alone, it is very common that, even with larger aquariums, they can easily become overcrowded. This can happen in the span of a couple of months.
Overcrowding can lead to a number of issues, from lower oxygen levels to ammonia spikes and fights breaking out. Unfortunately all of these issues can prove fatal to your aquatic community.
Solution
One of the easiest solutions is to only keep male or female guppies. This way your guppies wont be able to breed and thus your aquarium wont get overcrowded. Most aquarists that choose to go down this route will opt for a male only setup, because they usually display brighter colors. Although this can still lead to bullying and fighting among the men.
Going with a female only setup will still require you to keep an eye out. If a female guppy has been impregnated by a male guppy before, they could have stored some away and use this at a later point in time to become pregnant again.
In case this happens, or you have a setup with both males and females, you will at some point have to deal with fry. Good options are to contact your local fish shop (LFS) to see if they are able to take the guppies off your hands, or you could try to sell them yourself and make a little bit of profit.