Informational Guide

Water Heater Anode Rod Aluminum Vs Magnesium

by Andrew

The anode rod in your water heater is a critical part of the function of this device. Most people are not aware of what an anode rod is or what it does, but this is information that can impact the overall performance of your water heater, and it is worth knowing.  

The anode rod prevents rust formation inside your hot water heater and treats the water with the assistance of electrons. As a homeowner, you should know the difference between water heater anode rod aluminum vs. magnesium styles.  

This information can keep your hot water heater working properly and make sure that you will not be troubled by hot water heater performance issues. 

This guide can help you to find out more about the anode rod and what its function is within your hot water heater. 

The anode rod in your hot water heater can be made from various metals that help treat the water through electrolysis. This process makes sure that your bathwater is always fresh and that there is no corrosion inside your water heater's tank. 

Aluminum is the most common choice for this task because it works the best for various water hardness levels. You might need to select a different anode rod if you live in a location that has very hard or very soft water, as this can impact the acidity of the water inside your hot water tank in different ways. All anode rods will wear out over time, since this is essentially their job. They are placed inside your hot water heater to take the damage that your hot water unit would otherwise absorb itself. 

anode rod

Pros & Cons  

The Good  
  • Works well with many kinds of water 
  • Less expensive than some other materials 
  • Perfect for hard water 
  • They usually only have a small amount of zinc in them 
  • Can help with rotten egg smells in water 
The Bad 
  • Corrosive material from aluminum can sometimes break free and fall to the bottom of the tank 
  • Will not last as long as a magnesium rod in some cases 

What Is A Magnesium Anode Water Heater Rod? 

Magnesium anode rods work in the same way that aluminum rods do. They are placed in the hot water tank to attract corrosive elements that would lead to breaking down of the water tank. Magnesium anode rods are not suitable for every kind of water type, and in the wrong water, they can lead to rotten egg smells in your water.  

These anode rods contain a lot of zinc metal in them compared to aluminum rods which makes them good at reducing strong smells in softer water types. These rods are commonly installed on the cold-water feed and can contend with high chlorine levels and chloramines. 

water heater enclosure

Pros & Cons  

The Good  
  • Great for high chlorine content water 
  • Keep debris and sediment from forming in your tank 
  • Good for water with a lot of smell to it 
  • Can impart helpful minerals to water 
  • Provides excellent corrosion protection 
The Bad 
  • Higher in price than some other kinds of rods 
  • Rotten egg smell can result due to too many minerals being released into some water types 

Aluminum Vs. Magnesium Anode Rod: Which Is Best For Your Water Heater? 

Replacement Frequency 

The aluminum anode rod in your tank will need to be replaced every 1-3 years or if it has been 50% or more consumed. The frequency is the same with a magnesium anode rod, and you will also need to abide by the 50% or more rule. These rods can be broken down at different rates due to the kind of water that you have coming into the tank. 

Effectiveness Against Corrosion  

Both of these kinds of anode rods are effective at preventing corrosion, but they work best in different types of water. You will find that magnesium rods are more effective when used in screw-in applications and added line-in to the cold-water intake. They will help make the water alkaline in these applications, and they deal well with high chlorine levels. On the other hand, aluminum rods are perfect for water with lots of sulfates, and they handle corrosion quite effectively due to their durable nature. 

Sediment Build-Up/Formation 

The aluminum rod can sometimes shed debris and sediment into the bottom of your hot water tank, while a magnesium anode rod will rarely do this. You will probably not notice a major difference in performance due to this issue overall. Still, in some water types, the sediment collection properties of one rod over the other might be preferable.  

Health Concerns 

Aluminum is associated more frequently with build-up and debris that falls to the bottom of the hot water tank. This does not usually pose a health risk, but it can lead to water that is not as pleasant to use. Most homes have filtration systems on their drinking water systems, so this is often not a concern just due to this added layer of protection. Magnesium rods can lead to bad smells in the water when used with the wrong water type, but this is not a threat to your health. 


Both kinds of rods can lead to poor smelling water if the wrong style of rod is selected for your unique needs. You will find that aluminum rods are much less likely to cause these issues than magnesium. If you are worried about bad smells in your water, you will need to know what hardness and mineral content your water has to begin with. This can help with choosing the right anode rod style for your needs. 

Water PH Levels 

The pH of your water can also impact your choice of anode rod. If you have soft water with lower pH levels, you will want to get an aluminum anode rod. If you are dealing it the opposite problem, you might want a magnesium anode rod. 

Ease of Installation  

Most homeowners can handle this installation process themselves with ease. You will find that the only steps that need to be taken are that you will need to turn off your water heater, and you will need to cut power at the circuit breaker for your unit. This will make sure that you are perfectly safe while you are replacing the anode rod. You will simply remove the insulation above the rod at the top of the heater, unscrew the rod and then screw in the new rod. Replace the insulation, and you are done! 

plumbing installing rheem water heater


Magnesium anode rods are usually more expensive than aluminum rods. Neither item is prohibitive in cost, so you should not be worried about this part costing an arm and a leg. Many anode rods are about $50 new, but you could pay more for specialty rod types. 

Suburban Aluminum 232768 Vs. Magnesium 232767 Anode Rods 

Suburban anode rods are some of the best on the market today, and they make many kinds of anode rods for different hot water heater needs. You will find that they sell both an aluminum and a magnesium rod for your use in your hot water tank. These are some of the best anode rods on the market today, and you will get outstanding durability from them as well as great performance for your water quality and hot water heater longevity.  

Their magnesium rod is made to absorb corrosive action from hot water in the heater tank and can extend your water heater life. It is safe to use in an RV as well as for home use, and you will be able to order this product in packs of 6 if you wish. You will get a great quality product that will hold up to years of use and abuse and that is easy to install in your water heater tank. 

The brand’s aluminum anode rod promises to extend the life of your water heater tank and to absorb corrosive action as well. This is a single pack, which is slightly more expensive than the magnesium product. That being said, this might be the perfect choice for your hot water heater style and the kind of water you have in your location. Either of these products will help keep your hot water tank fully operational with ease, and you will just need to pick the right version of the product for your unique needs. 

Suburban 232767 Water Heater Anode Rod
  • Magnesium anode rod
  • For use in RV water heaters
  • Absorbs the corrosive action caused by hot...
  • Extends water heater tank life

People Also Ask (FAQs)

Are anode rods universal?  

These products are not universal. There are different lengths and sizes of anode rod, and your hot water heater might need a unique size that does not match common sizes. RV water tanks are often smaller as well and can need different size anode rods. When looking at an RV water heater anode rod aluminum vs. magnesium, you will need to consider the side of the unit and the kind of water that you are using in it. If you are running water that is very soft or very hard, this can change your buying decision for the type of anode rod that you need. 

Can you cut a magnesium anode rod? 

Yes, you can cut into these rods if you have to in order to replace them. This is usually done with a saw, and you will need to be careful that you do not damage any other parts of your hot water heater as you do this operation. Be careful that you wear gloves and watch your fingers as well since you will be working in a tight space. 

How long will a water heater last without anode rod? 

A hot water heater will last about 1-3 years without an anode rod. The lifespan of your water heater might be more or less depending on the kind of water that you have in your area, but no matter what, you will get a much shorter lifespan out of your water heater without an anode rod.  

How do I know what size anode rod to buy? 

You can find out what size anode rod you need by measuring the full height and length of the tank. You will be able to look at your owner’s manual as well to confirm the size anode rod that your unit is made to use. You can have standard sizes cut down if need be, but it is always better to just get the right size anode rod for your unit. 

How do I know if my anode is bad and needs replacing? 

There are a few signs of a bad anode rod. For example, you might experience a rotten egg smell or other bad smell in your water. You might also notice reduced heat or hear strange noises when your hot water heater is operating. 


This guide should have given you a lot of information about what kind of anode rod you need for your water heater. You will need to know what your water is like and some information about your hot water heater size and style to pick the correct anode rod for your needs. Picking the right anode rod is important for the overall lifespan of your hot water heater.