Why is My Guppy Not Eating? 5 Common Reasons

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As a guppy keeper, you probably have a lot on your mind. Guppies are generally easy-going and easy to care for, so long as you provide them with stable living conditions. And this is where the problems begin to brew.

There are so many factors to consider when keeping guppies that many novice keepers tend to overlook some of them. This is the case with feeding, as improper diets can lead to guppies experiencing feeding problems.

Guppy fish will stop eating due to various reasons such as expired or bad food, high level of stress or bullying, poor water parameters, low oxygen level or low temperature, disease or parasites, or even pregnancy. It is crucial to identify and treat these problems in time.

In this article, we will dive into these reasons why your guppies may refuse to eat. Identifying the issues behind your guppies’ abnormal feeding behavior is crucial for their health long-term.

That being said, here are the most compelling reasons why your guppies may show diminished or even complete lack of appetite:

1. Expired Food

Feeding your guppies expired food will always backfire immediately. Many of your guppies will eat it if they have no other option, but they will avoid it as much as possible. You may see your guppies nibbling at some food in the beginning and then stop eating, leaving most of it to waste.

And you know that that’s abnormal based on their previous feeding patterns. At this point, you need to investigate the problem. The goal is to check whether the food is the problem or something else is at play.

There are many reasons why guppies may refuse food, including water quality, sickness, low tank oxygenation, etc. All these problems will come with their own warning signs. Look for signs like erratic swimming patterns, guppies appearing apathetic and with low energy levels, signs of illness, etc.

If nothing pops out, verify the food’s quality, especially if you’re using commercial-grade food like flakes or pellets. To prevent any food-related problems, always try to rely on live food or, at least, get your fish food from reputed merchants, only selling quality products.

2. Stressed Fish

Guppies can experience stress for a variety of reasons. These include:

  • Inadequate male-to-female ratio – Having more than 1 guppy male per 2-3 females will inevitably change the tank dynamics for the worse. Guppy males can be quite pushy during the mating season, bullying the females and stressing them out. This can cause them to seek refuge wherever they can and experience a lack of appetite.
  • Predatory tank mates – While guppies are friendly and peaceful, not all fish species are. Some may be incompatible with your guppies, leading to bullying and even predatory behavior and turning guppies into victims. You may see them swimming towards the substrate, constantly looking for hiding and avoiding the company of other fish. This will stress out the guppies, lowering their appetite, destroying their immune system, and altering their overall behavior.
  • Fluctuations in water parameters – Guppies are tropical fish thriving in warm, clean, and well-oxygenated waters. Any drastic fluctuation in the water parameters will affect their behavior and wellbeing. To prevent this issue, I recommend always checking relevant water parameters like temperature, oxygenation, ammonia levels, pH, TDS (Total Dissolved Solids), etc.

The signs of guppy stress may include reduced or complete loss of appetite, hiding behavior, erratic or static swimming, etc. Untreated, guppy stress can lead to a weakened immune system, leaving the fish vulnerable to parasites, illness, and infections.

3. Poor Water Conditions

Ideally, you should change at least 50% of your guppies’ water every week to prevent harmful bacterial accumulation, spikes in ammonia levels, and poor oxygenation. All these problems will accumulate and aggravate with time, soon transforming the aquarium environment for the worst.

Your guppies will immediately show behavioral changes like loss of appetite and display signs of illness or ammonia poisoning. Improper tank conditions will lower your guppies’ immune system, which can open the door to parasites and various health problems.

You can tell that your guppies are experiencing some problems by assessing their overall behavior and general look. Some of the signs to consider include:

  • Lack of appetite
  • Discoloring
  • Swollen or cloudy eyes as a sign of parasitic infections
  • Visible body injuries
  • Gasping for air near the tank’s surface, etc.

The good news is that all these problems are preventable. Just make sure to have a good filtering system in place, change the water regularly, and perform tank maintenance as necessary.

You should also monitor the aquarium’s parameters constantly to prevent ammonia buildup, low oxygenation, dangerous TDS levels, or any other issues along the way.

4. Sick Guppy Fish

Guppy illness is another factor that may alter your guppies’ behavior over time. There are a lot of illnesses that will affect your guppies, some of which include:

  • Ick or White Spots – It’s an easy-to-detect condition thanks to the distinct white spots that will cover the guppy’s body. If detected in time, the disorder is curable. If not, like any other advanced fish disease, it can turn deadly.
  • The Velvet disease – A contagious disorder that’s very much similar to Ick. The difference is that the white spots are now actually gold and will cause the fish to lose its skin in time. This can lead to a horrendous and painful death, and, what’s even scarier, it’s difficult to diagnose the condition in early phases.
  • Guppy disease – This condition is more like a parasitic infection caused by a parasite that will enter the guppy’s bloodstream. This parasite is usually harmless towards many fish tanks, except guppies and a few others.
  • DropsyDropsy is a common disease caused by a bacterial infection. Your guppy’s belly will fail to eliminate any fluids due to the bacteria affecting the fish’s liver and kidney. This will lead to swimming problems as the guppy will struggle with a bloated belly and a bent spine as a consequence.

All these conditions, and more, will disrupt your guppies’ feeding pattern. The ‘good’ news is that most of these health issues come with a variety of other symptoms, aside from the diminished appetite. This will allow you to discover the problem in time and act accordingly.

5. Guppy in Labor

Females will enter labor approximately 21 to 30 days since the mating. This will cause them to eat less or not at all, swim in place, or look for hiding spots among the tank’s vegetation.

This is no reason for concern since it’s typical behavior for a guppy female experiencing labor. Your job should be to identify these signs early, so you can move the female into a separate tank.

The labor may last for several hours, during which the female will deliver between 2 and 200 fry, depending on several factors. These include the female’s genetic makeup, tank conditions, food, etc.

Don’t worry if your guppy female seems to have no appetite. She will return to normal after delivering the fry.

How to Get Your Guppy Fish to Eat?

It all depends on the reason why your guppies aren’t eating. I suggest first looking for signs of dirty water or water parameters spiking beyond the safe thresholds. This is most often one of the causes for your guppies experiencing a lack of appetite.

Then you should look for signs of illness, which is particularly vital if the condition is contagious. And untreated bacterial infection can kill your entire guppy population in a matter of days.

If everything fails, look for signs of fish stress or pregnancy. A methodical and thorough approach will eventually reveal the cause, telling you how to solve the situation at the same time.


Guppies generally have a steady appetite. If your guppies show significant changes in their feeding pattern, approach the situation methodically and take appropriate measures immediately.

Remember, your guppies should eat once or twice per day at most and only what they can consume within 1 minute. In some cases, you can even feed them once every other day. It all depends on how you’ve set their feeding pattern up to that point.

Updated: November 10, 2021
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