single tank vs dual tank water softeners

Single Tank vs Dual Tank Water Softener: Which is Better?

Water softeners, a god-sent device for your skin and your pipes, are essential for a comfortable home in a hard water area. After all, limescale is an unsightly and unnecessary ‘defect’ of the piping system.

Imagine that limescale buildup that you see on someone’s bathtub coating your skin. Hard water, having magnesium and calcium, negates the cleaning properties of soap. It is also abrasive to the skin. It’s one of the reasons why some people get eczema.

And as for your pipes, limescale will coat their inner lining, which leads to lower water pressure and damaged pipes. Have you heard popping noises coming from your water heater before? That’s from limescale messing up your heating element.

So if you’re looking to get a water softener, you’ll need help deciding between a single tank or a dual tank water softener.

The choice will depend on your usage of water. The extra storage on a dual tank water softener gives you a more reliable system. But if you want something compact and don’t want to spend more than your price point, a single tank water softener will also do the job.

Read on to learn what sets them apart…

Single Tank Softeners

The biggest advantage of a single tank system is the price. As you may know, water softeners have a mineral tank where all the magnesium and calcium are filtered out, as well as a brine tank. Resin beads in the mineral tank are charged with salt ions. These beads’ pull out’ the unwanted minerals out of the water and release their salt ion as a result.

The purpose of the brine tank is to aid in the regeneration cycle. Once the resin beads in the mineral tank are depleted of salt ions, they lose their ability to filter limescale. When that happens, the water softener automatically flushes salt water from the brine tank into the mineral tank to replenish the resin beads with salt ions. The saltwater is then drained away.

All of this is done automatically by the system.

Meaning, a single tank system in actuality has two tanks, and a dual tank system has three.

Now, a single tank system will have a lower upfront cost simply because it is smaller. But, it also could have a higher upkeep cost. As time goes on, the salt in your brine tank will need a refill. Due to its smaller size, you are going to have to refill it more often.

The upkeep cost also depends on the softener capacity. The higher the regeneration per cycle, the lesser efficiency you will get. I talk about it more in this article.

And because the regeneration is pre-set, it can be quite inefficient. For example, you might be using less water today than you would normally do, but the regeneration will still happen as if you’ve used up all your water. So, in the long run, it will end up having a similar cost, if not more, to a double tank due to the inefficiency.

Besides that, the single tank water softener is also compact. A water softener needs to be installed at the mains water supply, so that’s one advantage of the single tank. If you’re tight on space, this is the choice for you.

And the last disadvantage is limited tank space. If you use more water than your typical daily usage, like on a Sunday when everyone is home, then your mineral tank might be depleted. Hard water will then be able to flow through your home.

Dual Tank Softeners

Is your home a full house with teenage girls hogging the showers?

Well, if you have a big household, then you need a dual tank softener. A double tank has 2 mineral tanks(duh) which provide non-stop operation. This is because while one tank is regenerating, the other tank will provide you with soft water.

There won’t be a need for timers. Regeneration happens simultaneously. When your water usage increases, the dual tank works harder. There’s less wastage as it doesn’t use saltwater needlessly, saving you money on refilling the salt.

This leaves you with no hard water running through your home. It is economical and easy to use.

The downside: it can get pricey. Because the system is more complex, be prepared to pay more. The price gap is not small, mind you. But if you can afford it, then you’re getting what you paid for… consistent soft water at your demand.

Another downside is the size. A dual tank water softener needs a lot more space than a single tank. Some brands might be small enough to fit under a sink, but these are portable. A normal dual tank softener will not fit under a sink, so you’re going to have to store it in the garage or pantry.

Which Type of Softener Is More Efficient?

The dual tank water softener is undeniably the winner.

A dual tank water softener will use the salt more efficiently. In contrast, a single tank water softener will run a regenerating cycle regardless of the salt ion content in the resin beads.

A dual tank water softener will not run out of soft water. A single tank, on the other hand, might run out of soft water and revert to hard water on a laundry day. I think this makes the single tank inefficient as it has moments where it does not deliver on what it’s supposed to do.

I’m sure you agree that dual tank water softeners are the clear winner, simply because they deliver what you need more efficiently, but with the higher upfront cost.

Which One Do You Need?

Well, that depends. While the dual tank is the better system, you might not need a Ferrari. A Prius might suffice.

What you should do is ask yourself…

  • Is this for my business or my home? For example, if you’re running a restaurant or a laundromat, you’re going to need a constant supply of soft water. You don’t want the tank to be empty and have hard water introduced into your system the way a single tank does.
  • How big is my household? If you’re a bachelor, a single tank will suffice. The regenerating cycle will run at night and you can configure the timer to reduce wastage. On the other hand, if you have a big family living under one roof, it’s wise to get a dual tank system.
  • How much do I care about the environment? I apologize for being too forward, but it’s an important question. If you care about the environment, then the dual tank is your choice. I should also mention that single tank systems are not polluting machines that’ll turn sewers into swamps, but the difference in efficiency between the two systems is noticeable.
  • Do I have the space to store a dual tank system? Not everyone will have a home garage. If space is an issue for you, a single tank is your best bet.
  • How hands-off do you want it to be? Single tank water softeners use timers and require you to do some configuration. Not a bad thing, really. But if you’d like to have something that requires little thought, the dual tank is the way to go.


Do Dual Tanks Softeners Reduce The Pressure?

Both single tank and dual tank water softeners can reduce your water pressure if they are clogged or if there is an issue with the resin bed. Contaminants like algae, sand, or iron will slow down your water pressure.

To find out if your water softener is the cause of your pressure problems, use the ‘bypass’ valve on the water softener. If there’s no improvement in your water pressure, then the problem lies elsewhere.

A single tank softener may drop the water pressure if it’s not sized properly. If the tank is too small to store your daily water usage, then you will experience a drop in pressure during peak usage. That’s why it’s important to install the correct size of softener for your home. Dual tank systems handle this better; they speed up during peak usage and slow down if it’s not being used.

How Often Do I Need To Refill The Salt For Single Tank/Dual Tank?

Hard to say. This depends on the size of your household, how hard the water is in your area, and the type of system you have.

Obviously, more water usage equals more softening, equals more salt used. And if the water in your area has high amounts of magnesium and calcium, then more salt will be used. Finally, a dual tank is more efficient with its salt usage.

An average family of four, with the water hardness being around 7-10 grains of hardness, will use up around 40lbs of salt per month.

Final Words

And there you have it… everything you need to know about a single tank and dual tank.

The one you choose will depend on your circumstances. If you require 24/7 soft water, go with the dual tank. If you’re a bachelor or a small family, a single tank is a great choice.

My house uses a dual tank water softener, simply because I prefer having soft water all the time, and also because I don’t like to waste.

So I’m curious to know, for all the single tank users out there.

Have you ever run out of soft water and had hard water introduced into your system? Does it happen often?

And for dual tank users.

I’m curious to know where you place them. Is it in the garage?

Do let me know in the comments section below.

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1 thought on “Single Tank vs Dual Tank Water Softener: Which is Better?”

  1. There are several pros of dual tank. It is energy efficient during the filter process, no need to schedule recharges or set a vacation mode, no interruption of soft water. More importantly, it has lower operating costs. However, a dual tank takes up more space and a higher initial cost.

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