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Does Fish Food Cause Ammonia Levels To Spike?

One of the most common mistakes that we see time and time again with people who are new to the fish keeping hobby is that they will accidentally end up overfeeding the fish in their tank resulting in large amounts of food being left over that then ends up causing problems.

This is why there are so many people asking if fish food can cause ammonia levels to spike in their tanks so we wanted to cover it in today’s article to try and help as many of our readers as possible.

Leftover fish food in an aquarium can quickly cause ammonia and nitrate levels to spike in the tank which can then start having an effect on the health of the fish due to poor water parameters.

The longer the discarded fish food is left to sit on the substrate in the tank to decompose the worse the ammonia production can become too.

It can be common for people new to fish keeping to accidentally pour too much fish food into their aquariums but thankfully, a cheap gravel vacuum can quickly clean it up.

If you are having problems with your ammonia levels spiking then getting a cheap gravel vacuum or something that will eat the leftover fish food such as nerite snails, cherry shrimp, or a pleco if your tank can support it can be a great option.

Does Ammonia Spike After Feeding Fish?

If you are adding the correct amount of fish food to your aquarium then there should be no problems with ammonia levels spiking after feeding as your fish will eat all of the food.

This prevents there being leftover fish food in the tank that is then left to fester and spike your ammonia levels but overfeeding is very common within the fish keeping hobby.

Technically, as the fish food is then turned to fish poop it will increase ammonia and nitrate levels in your aquarium but a regular tank maintenance schedule of running a cheap gravel vacuum over the substrate in your aquarium really should be enough to prevent this.

If you are testing your tanks water parameters frequently enough to notice that you are having problems with your ammonia levels then it is highly likely that you are doing some sort of tank maintenance.

Something that is common with beginners is that they will just do a partial water change in their aquarium as their only form of tank maintenance.

Although this can temporarily lower the ammonia levels in your tank due to the freshwater, the leftover fish food is still left in the tank if you don’t use a gravel vacuum or something to eat the leftover fish food so ammonia levels will increase again quickly.

Why Do People Say Fish Food Causes Ammonia Levels To Spike?

Overfeeding fish is so common within the fish keeping hobby that it is very common for people to think that just feeding their fish will cause their ammonia levels to spike.

Provided you try to feed your fish the amount of food that they require this really shouldn’t be a major problem for the majority of setups.

Some types of fish food are technically more prone to being able to spike the ammonia levels in your tank too due to their contents.

This is usually the standard, cheap omnivore based fish food products that have low quality ingredients in them.

The higher quality fish food products that are specifically designed for herbivorous fish or the ones designed for carnivorous fish usually have better ingredients that will take longer to cause problems with your tanks ammonia levels.

Freeze-dried fish food options are also usually relatively slow cause of ammonia developing in a tank even if the food is not initially eaten by your fish.

This is due to the fish often foraging for any of the freeze-dried food that was not initially eaten as the majority of fish species seem to really enjoy eating freeze dried bloodworms or daphnia.

How Can You Stop Ammonia Levels From Spiking Due To Fish Food?

The easiest way to stop ammonia levels from spiking due to fish food is to try and reduce the amount of food you offer your fish to a level where they eat all of it.

Second to that, adding bottom feeders to the tank that will eat the leftover fish food is another great way to prevent fish food from being left to spike your tanks ammonia levels.

You have to realize that all of the common options for eating leftover fish food, nerite snails, cherry shrimp, and plecos also have their downsides too.

Snail poop and pleco poop can quickly become a real problem in tanks that use them as members of their clean-up crew due to how much they eat resulting in a large amount of poop being produced.

This can usually result in the tank having problems with its water parameters anyway due to the amount of poop spiking ammonia and nitrate levels anyway.

This is why many people who add snails, shrimp, or a pleco to their tank to eat the leftover fish food will usually still need to get a cheap gravel vacuum to clean up the fish poop before it can spike the ammonia levels anyway.

Are Water Changes Enough To Prevent Ammonia Spikes Due To Fish Food?

Water changes are not enough to prevent ammonia spikes in an aquarium due to leftover fish food.

Many people new to the fish keeping hobby seem to forget that the decomposing fish food at the bottom of their tanks is what causes their tanks ammonia levels to spike so you really do need to remove the root cause of the ammonia.

We know that there are posts on social media saying that a weekly partial water change in an aquarium is enough to deal with ammonia problems in an aquarium but it really isn’t.

It is a temporary fix at best and the more decomposing fish food you have at the bottom of your aquarium, the faster the nitrate levels in the tank will spike can cause problems resulting in water changes being required on a more frequent basis.


That brings our article going over if fish food causes ammonia levels in an aquarium to spike or not to an end. We hope that we have not only been able to help you understand that fish food, especially the cheaper fish food options can cause the ammonia levels in your aquarium to spike at a rapid pace. In addition to that, we hope that we have also been able to help our readers understand that it is usually much easier to just get a gravel vacuum to remove the left over fish food in their tank once or twice per week than the other common options to deal with the problem too.