Is it time to replace your water heater anode rod? Take five minutes to learn the pros and cons of each type of anode rod before you buy another!
An aluminum or magnesium anode rod aids in preventing corrosion, rusting and leaking of the water tank. It attracts iron, limestone and other minerals in water, so that the tank stays clean and functional.
In today’s water heater anode rod aluminum vs magnesium comparison, we’ll talk about their key features, cost, ease of installation, longevity and benefits.
Want to choose the most suitable anode rod for your water heater unit and pH? Then make sure to keep reading!
Top 5 Differences Between an Aluminum Anode Rod and a Magnesium Anode Rod
An anode rod releases electrons in the water and therefore, saves your water tank from rusting. If you want to know which anode rod is going to be the best, it’s good to compare your options against these seven factors.
Smell of the Water
Water heater anode rods are known to produce a certain type of odor. If you want to buy a no-nonsense water heater, the smell of the anode rod can tip the scales. Magnesium anode rods are highly reactive and may produce hydrogen sulfide, a chemical that makes water smell of rotten eggs. You can always try to clean your water heater with vinegar to help with this issue.
This is why a standard anode rod is made of aluminum and a little bit of zinc. For one, they do not behave the same way with bacteria as a magnesium anode rod. And two, adding zinc neutralizes the strong, unpleasant odors often created during the electrolysis process.
The acidity of water is a big concern while choosing your water heater anode rod. Most rods don’t perform well in hard water, which leads them to premature corroding.
Hard water is more alkaline with a high pH level. Because of the unique properties of an aluminum rod, it withstands hard water much better than a magnesium anode.
Therefore, aluminum anodes are the best option for a hard water heater tank. Magnesium anode rods are more appropriate for homes with soft water. Soft water has lower pH, and magnesium is expected to work better in lower acidity.
If your house is starting to smell like hydrogen sulfides, it means that the anode rod is not a good fit for the water pH. Replacing it with a zinc-aluminum rod can fix the issue.
Compared to other anode rods, aluminum has a distinct problem. Aluminum anodes tend to create dissoluble byproducts. They accumulate at the bottom of your hot water heater and make the rod itself grow bigger. With time, the mineral buildup can cause your heater unit to run loudly.
If you’re using aluminum anode rods, corrosive elements can wash into the plumbing fixtures with time. Some of them may rise to the top of your water heater. They form a sticky substance which, in higher volume, can clog your tap aerators, filters, and plumbing system.
As mentioned, magnesium anode rods are used with softer water. However, they don’t last as long as their aluminum and zinc counterparts. It’s because magnesium is more reactive and receives a higher voltage from your heater unit.
Therefore, a magnesium anode will wear out much faster than aluminum. On average, aluminum anode rods last about 3 to 5 years. It really depends on the acidity of the water and how much water passes through the heater every day.
Sacrificial anodes go through a slow yet constant corrosion process. Aluminum corrodes slower than magnesium but it has some serious benefits.
In this aluminum vs magnesium debate, what eventually works for your water heater will be based on the water quality, pH, and volume. Both anode rods can prevent corrosion in your tank-based water heater.
Magnesium Anode Rod
When it comes to efficacy, magnesium anodes are better. Magnesium is a sacrificial metal that thoroughly protects water heaters from rusting out. Because they react so fast, you might need to replace your old rod with a new anode rod in a few years’ time.
Magnesium can decrease a bit of the scale that inevitably forms inside a water heater as a result of high alkalinity. Professionals also recommend magnesium anode rods for water with high chlorine levels.
Aluminum Anode Rod
Aluminium rods react too slowly with cold water- so much that corrosion may not be avoided in the end. Not to mention, the harmful sediments created by the heater anode can damage your water filters at home.
Note that if a water heater anode rod is completely dissolved, the water is no longer safe to drink. To be safe, use the tank water only for cooking, cleaning and showering purposes. It’s not recommended for consumption without boiling the water early on.
Tank-based water heaters will need a change of sacrificial anode rod every few years. Just aluminum rods, without the addition of zinc, will cost less than magnesium anodes. Aluminum is an abundant resource, which makes it a good choice for heater units. It’s affordable, lasts longer and doesn’t produce hydrogen peroxide as much as its magnesium counterpart.
Aluminum-zinc anodes are a bit pricey because zinc is very good at neutralizing the rotten egg odor. Magnesium is more expensive, and given how fast soft water eats up a magnesium anode, you may look at its alternatives.
In our opinion, if you have hard water coming through the pipes, you should get a water softener. It can reduce mineral build up inside plumbing fixtures and water heater tanks. Always put the water softener before the water heater, rather than installing it downstream.
Ease of Installation
A magnesium anode will protect your water heater for a shorter period. But if you’re willing to change it in due time, you can actually save your expensive water heater from hundreds of dollars worth of upkeep. Another thing we like about a magnesium rod is that it requires an easy screw-in application.
By attracting corrosive elements, an aluminum rod can grow twice in size inside the water heater. Therefore, magnesium anode rods are a safe option. We personally find screw-in applications more convenient for tank-based heaters.
If you find the whole aluminum vs magnesium thing stressful, you can explore tankless water heaters. These units don’t require an anode rod at all.
Frequently Asked Questions
Is magnesium anode better than aluminum anode rod?
Magnesium rods don’t produce solid/semi-solid byproducts. The water heated by a magnesium anode is also safe. So, even though they produce a hydrogen peroxide smell, magnesium rods are better than aluminum rods.
How often should I replace my water heater anode rod?
Depending on acidic water conditions and the volume of water that enters your water heater, you should replace the anode rod anywhere between three to five years. It’s best not to wait longer since some of these anodes can swell up, dissolve entirely and make your water heater explode from the pressure.
What’s the main difference between aluminum anode rod and magnesium anode rod?
The main difference between aluminum anode and magnesium anode is their chemical reaction with water and its minerals. Magnesium releases ions more easily than aluminum, preventing highly alkaline water from damaging the tank.
Which anode rod is the best for hard water?
Aluminum or aluminum-zinc anode rod is the best for hard water. You can use a flexible anode rod as well but it doesn’t compare to solid aluminum anodes. Magnesium erodes at a faster rate than aluminum, and overall, is not an ideal choice of hard water anode material.
A long-lasting water heater, safe water, smooth plumbing in every room- if you want all three of these things, you’ll get a magnesium rod. It doesn’t produce any corrosive material in the form of floating sediments.
Unlike an aluminum anode rod, dissolved magnesium has health benefits. It’s pretty clear which side wins in our water heater anode rod aluminum vs magnesium comparison.
Lastly, if you compare zinc anode rods with either of today’s contenders, you’ll see that a zinc anode rod and a magnesium rod are indeed better than just aluminum rods. Thanks for reading!
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