Can We Compost Fish? How?

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In Brief: Can We Compost Fish?

Yes, we can compost fish meat, scraps, gut, bones, and skin with reasonable care and attention. They can be either buried or composted in enclosed sturdy bins. It helps in keeping away the scavengers. One tip is to provide generous amounts of high-carbon materials, including straw, leaves, sawdust to increase aeration and help in decomposition.

This is an ultimate guide on whether one can compost fish. If yes, how?

Shall we learn more?

Can We Compost Fish?

Fish scraps may be mixed with plant waste and composted. It helps in eliminating odor and deterring scavengers.

Yes. We can compost fish including meat, remains, bones, skin, and gut as they are organic. But, they require special care and attention.

One issue is that fish scraps may turn anaerobic and become rancid as they decompose. They attract rodents, foxes, flies, and other vermins due to their strong odor. So avoid adding them to the regular compost bin.

The fish waste should be mixed with plant waste to increase aeration and balance the high nitrogen. You may add in the center to deter pests and facilitate the decomposition.

It is preferable to clean the fish and add them to avoid dangerous bacteria. As the microorganisms decompose fish, they generate heat that may help in eliminating odor, killing weed seeds, and pathogens.

How To Compost Fish With Ease?

The fish scraps may be buried in a deep pit or composted in a closed bin. It is recommended to mix plant waste with them.

You may compost fish scraps in the pit or a closed bin.

Method 1

Add fish scraps in a pit – Dig a pit in the garden about 18 inches deep. Add about 6 inches of fish scraps in the pit.

Add high-carbon material – Mix them with high-carbon materials, including shreddy brush, wood chips, leaves, straw, or sawdust.

Cover the pit – Cover them with enough dirt to about four inches.

Protect the pit – Enclose the pit with a sturdy fence or wall. Top it with a scavenger-proof frame. The resultant compost may be dug after several months.

Method 2

Here is another method to compost fish –

Set up closed composter – Use a fully enclosed composter, like a compost tumbler.

Add fish scraps and organic matter – Cut fish meats into small pieces. Mix them with plant waste and buried at the center.

Collect the compost – You may get humus after several months due to the action of microbes.

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How Long it Takes Fish to Compost?

The full process can take 3-4 months. The duration of fish to decompose depends on pH, temperature, carbon content, and size of the compost pile. The process will be faster if the conditions are ideal. The duration of fish decomposing depends on several factors. It requires a pH of 6-8.5 and a temperature of 54 C-65 C during decomposition. It needs about 60% water to 20% oxygen.

The pulverization of fish bones and chopping of fish meat may speed the decomposition process. The ideal size of a compost pile is 10 cubic feet.

The decomposition may be faster if these ideal conditions are provided.

Can You Compost Cooked Fish?

Yes, cooked fish can be computed. A great way to do so is by the Bokashi method. It makes use of anaerobic bacteria and bran to ferment cooked fish.

Cooked fish require special attention as they do not decompose well and attract flies and vermin. They may turn mushy and decay soon that may interfere with the aeration of the pile.

You may use the Bokashi method to ferment. The cooked fish is added to the closed bucket with a sprinkling of bran over each layer. The fermented waste may be added to a compost trench or a hole in the ground.

Can You Compost Fishbones?

Yes, fishbone can be composted. Fishbones may be ground after baking and added to the compost pile. It requires a closed bin to keep away from troubling vermins.

Fishbones are an important source of calcium and other minerals. It is recommended to use a big and closed composter to avoid vermins digging them.

You may grind up fishbones and add them to the compost pile. They break sooner in hot compost systems.

You may also bake the bones in low heat until they are crumbly. Pulverize the baked bones and add them to the compost pile. This will not attract pets and fasten the decomposition process.

Benefits of Fish Compost

Fish compost may help in increasing soil nutrient content, decreasing parasites, and eliminating weed seeds. It also enhances the growth of plants.

Fish compost is a good soil amender by providing the source of nitrogen. It may increase the productivity and resilience of plants.

It may help in protecting the water resources from fish waste contamination and maintaining the ecological environment.

In addition, it may help in decreasing parasites, restraining plant diseases, promoting water holding capacity, and eliminating weed seeds.


Can you compost fish heads?

Yes. But you may need twice the amount of high-carbon brown material to cover the mixture at least 3 inches deep. Secure them in a compost bin from animals. Else, bury them at least 12 inches deep.

Is fish compost good for plants?

Yes. Fish compost may be added to the plants to improve soil health. It provides a source of burn-free nitrogen, phosphorus, and valuable micronutrients like iodine.

Bottom Line

I hope this article has helped you understand if fish can be composted. If you have tried any other method, please do share it with us.