Too Much Water In My Brine Tank

This guide helps homeowners interpret what they’re seeing when checking the water and salt levels in their water softener’s brine tank.

Here at Aquatell, we get all kinds of tech support requests about the level of water in the brine tank. This post is about helping people to better understand which observations to worry about, and which ones to not worry about.

Spoiler alert - most of them you don't need to worry about!

Here are the general categories of questions we get:

1. How much water should be in the brine tank?

2. The water in the brine tank is above the salt and that's a problem, right?

3. The brine tank is full of water all the way up to the safety float.

And here's what we think about these:

How much water should be in the brine tank?

It depends! The volume of water in the brine tank is a way of thinking about how much salt the system needs to properly regenerate. The salt that's dissolved in the brine tank is what the softener uses to recharge the resin when the system regenerates. The amount of salt that's needed (and the resulting amount of water needed to dissolve the salt) is going to depend an a few things:

The size of the softener (i.e. how much softening resin it was built with) and the resulting volume of brine it needs to properly regenerate

The salt dosage used in the programming (different water conditions demand differing amounts of salt be used, thus differing amounts of water in the brine tank)

The size of the brine tank. If you add X amount of water to a small brine tank, the water level will be higher than adding the same amount of water to a larger brine tank

The type of salt used. Different salt brands have different sized crystals or pellets. If the salt crystal size is small, this leaves little room for water and this pushes the water level up higher. If there are larger spaces between the salt crystals more water can sit between the crystals

If there is a brine grid used. This is a perforated plate that sits on the bottom of the tank and provides a place for the brine solution to sit and not be displaced by salt. If a brine grid is installed on the brine tank, the brine tank water level will be lower.

When you check the level. If you just added salt to the brine tank, the undissolved salt will push the water level up higher. If the softener has very little (or no) undissolved salt in the brine tank, the water level will be lower.

The water in the brine tank is above the salt and that's a problem, right?

As an observation by itself, the level of the water relative to the level of the salt is pretty meaningless. And it makes sense if you think about it for a little while. If you have X amount of water, and there is no salt in the brine tank the water will reach up to a certain level. If you add a bag of salt to this water, some salt will be dissolved, but most will not, and this will displace water and drive up the water level in the tank. If you add enough salt, the undissolved salt level will be higher than the water level. So, the amount of water didn't change at all (and the resulting "regenerating power" of the softener). Only the undissolved salt amount changed.

What we thinks drives most of these questions is the notion that the amount of salt relative to the water somehow affects softener performance, but it doesn't. If the water is above the salt level, at the salt level, or below the salt level, it contains the same amount of dissolved salt. That's the important thing.

Now, there might be a case to be made that having excessive "dry" salt above the water level could result in more salt bridging (where it sticks to itself and causes a sort of salt log-jam) but we haven't seen evidence that this alone causes this. It seems to be more related to the chemistry of the water that is in the brine tank and if the softener fills the brine tank with softened or non-softened water (differs by model).

The brine tank is full of water all the way up to the safety float.

Ah, now we're circling around an actual problem that might need to be addressed. The observation that the water in the brine tank has reached it's maximum level often indicates an issue. "Maximum level" is the water level that engages the float mechanism of the softener, or the level where the brine water level reaches the overflow and either flows out of the brine tank, through the attached overflow tubing and to drain, or if no floor drain is available, it spills onto the floor. The "max water level" condition is usually caused by two different conditions:

a) The softener isn't programmed properly

The softener programming will have a mechanism by which the installer defines how much water should be added to the brine tank. Different softeners have different ways of defining this. Some systems will have a "salt amount" that then translates to an amount of time that the softener fills the brine tank for (at a known brine fill rate). Some softeners will have "brine fill" function that the user sets in minutes. In these cases, the user typically needs to know the fill rate as most of these systems have different fill rates depending on the size of the softener. Other softeners will have a low / med / high salt setting that translates to the volume of water added to the brine tank. There are too many variations of this concept to get any further into the details on this. The post would be 10 pages long!

b) The softener isn't drawing the brine out of the brine tank during regeneration

This observation has to be made in real time during a regeneration. To do this, consult the manual of your softener to know how to manually initiate a regeneration or look for a button on the controller that says REGEN or Regeneration or looks like a triangle made of three arrows. Hold down this button for about 5 seconds and a regeneration will start. Often, this same button can be used to advance stages by pressing it again (but not holding it down this time). Usually, the second stage is the Brine Draw stage. When you get to this stage you'll usually see the word brine or draw or BD on the screen and the stage length will be long. Typically 60 minutes. When you get to this stage, leave the softener alone and keep an eye on the water level in the brine tank. The draw is slow. But after 10 minutes of this stage you should see an observable drop in the brine level in the tank. If you do, then the draw is working properly. But if you do not see a drop, the softener is not working and you've just discovered why the brine tank water level is maxed out: the softener is not able to remove water from the brine tank, but it is likely able to add it. So, over time, as regenerations occur, the water level in the brine tank rises, until it's maxed out. This usually only takes two regenerations under these conditions.

If this is what you find, here's that you need to investigate further to correct the issue:

1. Ensure you have an air/water tight connection at either end of the brine line. This is the tube that connects the brine tank to the control valve. Look for evidence of water leaks at either end. If either end of the brine line is not air/water tight, then the vacuum created in this line to pull out the brine solution is broken and the water in the brine tank can't be drawn out.

2. Most softeners have an "injector" that creates the vacuum/suction to pull out the brine solution, and a screen that protects the injector from debris. If either get jammed up, the unit can't create suction to pull the brine out. Look in your manual or online to figure out where the injector and/or screen is on your system, and clean them out. The observation that points to this, is often that the brine tank fills up with water during the brine draw stage when it should be draining.

3. Really old softener resin. If your water softener is really old and/or if it's been used for 10+ years on a chlorinated water supply, the resin might be shot. When this happens the resin swells and the softener can't push water through it very well. This interferes with the ability of the softener to generate the vacuum/suction during regeneration. The observation to watch for here is the same as #2: the brine tank fills up with water during the brine draw stage when it should be draining.

4. The softener drain line is kinked or blocked or frozen, or way too long. If the softener can't send water to the drain because it's blocked or because the length of the drain line is too long (and creates resulting backpressure) the softener can't generate a vacuum.