How to Get Iron Out of Hot Tub Water

Having iron and other metals inside your hot tub water is totally normal. What’s not normal is leaving the iron inside the hot tub and allowing it to build up. And no, we are not talking about solid steel. We are referring to the presence of ferrous iron and other soluble metals in the water in your hot tub.

Iron and metals like magnesium, copper, zinc, and the likes are present in the water you fill your hot tub with. Without getting rid of these metals, they would build up and cause problems later on.

So, how to get iron out of hot tub water? The best way to get rid of iron in the hot tub is to add metal remover or water softener to the water in the tub. But that’s just the quick answer.

If you see your hot tub water turning somewhat green then you probably have too much iron in your spa water. Don't worry. We will explain to you how to get iron out of hot tub water.

How Does Iron Get Inside the Hot Tub Water?

What do you fill your hot tub with? Water, of course, but where do you get the water? That’s the real question. Many of us fill our hot tubs directly with freshwater, or with the water from the well, or from the tap.

All of these water sources have a degree of iron inside them. Iron like magnesium, copper and the likes are usually present in water. Iron gets into the water through natural deposits, industrial waste, and even through the corrosion of metals.

The water that flows through your tap for instance has a degree of iron inside it. Most times, the water runs through metal pipes that have been laid for years. The corrosion of these metal pipes over the years releases iron and other metals inside the water that flows directly through the tap.

So when you connect your garden hose to the tap, you are directly filling your hot tub with water that has a high concentration of iron and other metals inside it. The same goes for the water you get from the well.

Can Iron in the Hot Tub Harm You?

The presence of these irons in your hot tub water would usually not cause any serious health problems. But, it can cause problems for the hot tub. When there is a build-up of iron in the water inside the hot tub, the pH levels of the water are altered.

This is because iron like magnesium and copper react harshly to the sanitizers you add into your hot tub water to purify it. The clash of these sanitizers like chlorine and bromine with the iron in the hot tub can turn your water green and can also corrode the shell, the jets, the headrests, and even the filters in your hot tub.

If the iron build-up is left unchecked and uncontrolled, you will find yourself repairing and replacing different parts of your hot tub sooner than later. So how can you eliminate iron from your hot tub water? Let’s find out.

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How to Get Iron Out of Hot Tub Water

Getting rid of iron from hot tub water sounds a bit farfetched since the iron comes with the water directly. Though it can be difficult to rid your hot tub water from iron completely, it is very much possible.

To get rid of iron from the hot tub, you’ll need to add products that are designed for getting rid of metals and irons from water. These products go by many names such as water decalcifier, water softener, metal remover, and the likes.

But before you add these products to your hot tub water, there are a few things to know. Follow the steps below to get rid of iron from your hot tub water.

Test the pH Levels

The first thing to do is to test the water to be sure you have too much iron in your hot tub. To test the water, take a sample of the water to a local pool store or a lab to have it professionally tested. The test results will show how much iron is present in your hot tub water.

Before getting rid of hot tub iron water you need to check your pH levels. The pH levels indicate if you have too much iron or not.

You can also test the water by yourself by using a digital tester or by purchasing water testing kits or test strips. Another alternative is to inspect the water by yourself. If you notice discoloration of the water in the tub, stains on the water surface and on the shell of the tub, then you are likely dealing with a case of high iron levels in the water.

Other indicators of high iron levels in the water include corrosion of the shell, filters, and other parts of the tub. If you also notice that the water starts to turn green whenever you add sanitizers like bromine and chlorine to the water, then that means there are irons in the water that are reacting to the sanitizers you added.

All of these are indicators of high iron levels in the water but the best way to be sure is to have the water tested.

Turn on the Jets

The next thing to do is to turn on the jets and keep the water running. The jets will ensure that the water in the tub is being circulated. The circulation of the water will ensure that the metal remover gets to every part of your hot tub.

It will also ensure that the metal remover is absorbed by the water evenly. Without turning the jets on, the water wouldn’t circulate and when you add the metal remover, it will just be concentrated in one part of the hot tub.  This can cause a high level of iron in one part of the hot tub and a low level of iron in another part.

Add a Hot Tub Metal Remover to the Water

When you have tested the water and you are sure you have too much iron in the water, you should add a hot tub metal remover to the water. Hot tub metal removers come in different forms. They can be a liquid solution or a powdery compound that needs to be scattered in the hot tub water. Ensure to follow the manufacturer’s instructions on the container of the metal remover you buy.

If the metal remover comes in powdery form, you might need to mix it with water first before adding it to the water in the tub. If the metal remover comes in a liquid solution, you might be allowed to add it directly to the water or you might need to mix it with water first.

Just make sure you follow the instructions. The wrong dosage can alter the water chemistry and cause another problem for you to fix.  While adding the metal remover to the water, ensure the water is being circulated and the jets are on.

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Clean the Iron Stain

One of the many negative effects too much iron has on your hot is discoloration and staining. The presence of too much iron in the water can cause a brown tint color on the shells and headrests of the hot tub. To remove the stain, mix water, and white vinegar in a bowl or bucket.

You can also go the extra mile and add 1 or 2 tablespoons of baking soda to the mixture. Be careful with the baking soda. It has a very acidic pH and too much can cause corrosion. After mixing the water with the white vinegar (and baking soda), use the solution to clean the stains on the hot tub.

You can pour a bit of the mixture into a spray bottle so it’s easier. Start by spraying the solution on the areas where you notice the stains and leave it for about 10 minutes. After 10 minutes, spray the solution again on the spot and use a rag to wipe the spot.

You can repeat this as many times as possible but ensure the mixture doesn’t get into the water. Just ensure you get all the spots that have been discolored by the presence of iron in the water.

It is usually advised to do this when you have drained the hot tub but you can do it with water in the tub. Just ensure the mixed solution doesn’t get inside the water. After this, have the water retested. You should notice a considerable drop in the iron levels in the hot tub water.

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Last Resort

If you have retested the water after adding the right amount of metal remover and the iron levels are still high or unchanged, then you should drain the hot tub. Chances are the water has been severely affected by the irons and this is usually caused by improper drainage of the hot tub. Hot tubs should be drained every 3 months.

If you haven’t drained your hot tub in a long while, that can be the reason for the extremely high presence of iron in the water. Draining the water will be the best if this happens. After you have drained the water in the tub, ensure to thoroughly clean the hot tub.

You should also remove and have the filters cleaned. A hot tub line flush should also be added to the plumbing lines of the hot tub because that is where you would have a build-up of iron the most.

If any part of the hot tub is damaged, have them repaired or replaced. Do all of these and refill the tub with clean water. This should fix the iron problem.

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How to Prevent Iron Build-up in Hot Tub Water

Use a Hose Filter

Whenever you want to fill the hot tub with water, use a hose filter with the garden hose. The hose filter will restrict most of the iron and solid metals that can flow into your hot tub water.

If you can, you should also stay away from well water when filling the tub. Well water has a high level of iron and metals in it and not only that, it is not the cleanest source of water to soak in either.

Related Read: How Long Does It Take For Hot Tub Water To Clear?

Add a Metal Remover to the Water Regularly

This will prevent a build-up of metals and iron in the water. You can add the metal remover once in two weeks.

Though the hose filter will prevent the bulk of the iron and metal that can get into the water, some iron will still get into the water. Adding a metal remover regularly will ensure these irons don’t accumulate inside the hot tub.

Clean the Filters

The filters trap dirt and debris that get inside the hot tub and can also trap iron and metals. If the filter is clean and in good condition, the level of iron and metal in the water will be reduced. Learn here how to clean spa filters.

Use a Line Flush

You should also add line flush to the plumbing lines of the hot tub once in a while. This will ensure the plumbing lines remain clean and free from iron and other metals that can corrode the shell of the hot tub.

Just in case you didn’t know: The water in the well comes from the soil and that alone can cause an increased level of iron in the water. So when you take water from the well and fill your hot tub with it, you are directly adding iron to the hot tub. That’s how iron and other metals get into the hot tub water.

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