How Much Miracle Mud Do I Need To Use?

In this article, I will show you exactly how much Miracle Mud to use in your saltwater tank.

This comprehensive guide will cover:

  • What is Miracle Mud?
  • How much Miracle Mud to use
  • Benefits of using Miracle Mud
  • Adding Miracle Mud to an existing tank
  • How to use Miracle Mud in a sump

Before adding any new product into your saltwater tank, it’s important to know how much to use.

Miracle Mud is one of those products where you need to use the recommended amount for it to be most effective.


Marine Depot Miracle Mud

What is Miracle Mud?

Miracle Mud is a mud substrate designed to be used in refugium and sump systems in saltwater aquariums. It will provide all the essential trace elements, minerals, and components needed to maintain a successful saltwater environment. 

It will replenish your aquarium’s concentration of these trace elements and minerals consistently. 

Miracle mud also acts as a denitrifying filter. It contains the anaerobic microorganisms that denitrify the aquarium providing pristine water conditions. 


How much Miracle Mud should you use?

The manufacturer recommends using 10 pounds of Miracle Mud for tank sizes between 40-65 gallons with filter box dimensions of 24 x 10 x 12 inches. Aim to have around 1-2” depth.


Here is a chart showing the recommended use for different tank sizes.

Marine Depot Chart


Miracle Mud also needs to be changed each year of use. You need to remove 50% of the Miracle Mud being used and replace it with new.

This will replenish the trace elements in your aquarium.

It’s important to not replace all of the Miracle Mud at the same time. 


Benefits of using Miracle Mud

There are many benefits of using Miracle Mud including:

  • Continuously replenish trace elements and minerals in your tank
  • Acts as a denitrifying filter
  • Reverses head and lateral line erosion in fish (HLLE)
  • Improved coloration of fish and corals
  • Can be used in fish only or coral reef tanks
  • Very easy to maintain
  • Affordable and effective

If you are looking to try Miracle Mud, it is available at Marine Depot here.

Buy Miracle Mud


Can you add Miracle Mud to an existing tank?

Yes, you can add Miracle Mud if your tank is already set up and cycled.

You will experience cloudy water for a period of time which will clear. Miracle Mud will not cause an ammonia spike. 


How to use Miracle Mud in a sump

Miracle Mud can be used in refugium and sump systems.

In your sump tank, you can dedicate the middle section to be used as a refugium which will contain the Miracle Mud.

Marine Depot Miracle Mud In Refugium

Place the proper amount of Miracle Mud in your refugium section to cover the bottom at around 1-2” depth.

When the Miracle Mud is wet and packed down, it should be around 1” deep. This is to ensure proper denitrification takes place.

Ensure all pumps in the aquarium are turned off.

Place either a plate or plastic bag on top of the mud and very slowly start to pour water onto it allowing for the water to disperse over the mud. 

It’s important to not pour water directly over the mud as this will stir up the mud causing it to be suspended in the water. This will create cloudy water and it will take a long time to settle back down. You want to eliminate that as much as possible.  

Once the Miracle Mud has settled, you should aim to have around 10-12” of water depth. Any floating particles can be removed with a net.

You can also use filter floss or padding in your sump after the refugium section to catch any debris and help keep the water clear.

Turn on your aquarium pumps and aim to set them at the recommended flow rate for the Miracle Mud. 

For a 40-65 gallon tank, it is recommended to have an 800-1000 GPH flow rate through the refugium where the Miracle Mud is located.

This will increase the efficiency of the mud. 

Here is an excellent video showing the placement of Miracle Mud in a refugium section of the sump.



Miracle Mud is a great product that has many benefits. It can be used when either starting a new saltwater tank or it can be added to an existing setup.

It’s important to follow the recommended amount of mud to be used for your tank size. This will increase its efficiency and provide the most benefits. 


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