How to tell if your septic tank is full? 1 Easy Step

If you know your home has a septic tank, it’s important to determine the level of occupancy. Some septic systems have a gauge to tell you how full the tank is. This system can be located on the front or back of the tank. If the reading system indicates that the tank is almost full, it’s time to call a professional to clean and/or fix any issues. There are other ways to check if the tank is full as well. Let’s discuss these.


 After how many months does a septic tank get full?

A septic tank should be emptied every 3-5 years. Most of the waste should go in the drain field. If you don’t have a drain field, it is possible that you have to clean it out more often. There are several factors that determine how often it has to be emptied:

  • Number of connected toilets
  • Size of the tank
  • If the tank also is connected with other systems
  • How well your tank works
  • If there are problems with your tank
  • The climate
  • The size of your drainfield

The tank might have to be inspected every year if it has complex systems such as pumps.

There are two types of septic tanks: single-family and multifamily. A single-family septic tank usually has one or more individual wells that discharge into the tank. The multifamily system is often used in high-traffic areas such as hospitals, libraries, and schools.

What is the septic system reading stick?

The septic system reading stick (or sludge judge) is a tool that you can use to determine if the tank is full. You have to insert this into the inlet T of your sewage tank (generally this is a plastic tube in or next to your tank). If you don’t have this tool, you can take a long pole and tape a sock on top of it. Push this to the bottom of your inlet T and check how much sludge is in your tank. If the sludge + scum is about 1/3 the height of your tank, you might have to clean it.

Other counties say that the tank should be cleaned when it is filled for 25% of the tank. Check the thickness of the scum layer (the first layer), this should be less than 2 inches. Also, check the thickness of the solid layer on the bottom. This should be less than 1/3 of the total tank. Check that there is no standing water on top as this can indicate a leak.

More modern systems have a sensor and can send a message when it is time to clean your septic system.

Most septic systems with a pump also have an alarm. This is used to indicate that there is a problem with the system. It is possible that too much water is being added to the tank and this can cause issues as well. This can fill up your tank as well.

It is a great idea to check the gauge every month to see how it evolves.

There are other ways to check if your tank is full though. Let’s talk about these now. 

 Check the color of the crust in your septic tank

The crust on top of your tank should be brown. You can check this when you open up the tank. Wear gloves and be careful when you do this. A white crust can indicate that you might have to do some maintenance to it. This is especially bad for concrete tanks as these can get eaten away by this.

Toilets not flushing properly

If your toilet isn’t flushing properly, it may be due to a full septic tank. The water is not able to flow away and gets stuck in your drains. This can backup things and you might feel that the toilet flush is not taking everything with it. This is quite simple to fix as the sewage tank just needs to get drained. The water can flow again once this has happened. Some people think that there is an issue with their toilet or drains but it is just the tank that needs to get pumped empty.

A gurgling sound when you flush

If you hear a gurgling sound when you flush the toilet, it’s time to call a professional to clean and/or fix any issues. This sound is indicative of a full septic tank and can be caused by many things, such as problems with the sludge in the tank, leaves or other debris accumulating in the tank, or even sewage spilling from the tank.

Bad smell coming from your septic tank

One common symptom of a full septic tank is bad smells. This can be caused by the sludge. To determine if the smell is coming from your septic tank, take a look at the readings on the system. If the readings are above normal, then it’s time to call a professional to clean and/or fix any issues. After a while, your bathroom or toilet might even be small bad as the P-trap can get backed up. Once this happens, you should call a company to help you out. 

Greener grass

A septic tank drain field is a field in which sewage is discharged into the ground to be eliminated by your septic system. Normally the sewage gets divided evenly over this area. If the tank is full, it is possible that it starts to leak and this can cause greener patches of grass. This can be quite noticeable, especially during drier periods of the year. 

Patches of water in the drainfield

If you notice patches of water in your drain field, it may be indicative of a full septic tank. If this persists, a professional should be called to clean and/or fix any issues with the system. The sewage should be spread out evenly over the drain field so that this area is fully used. 

Drain flies or other pests

Drain flies or insects are attracted to the sludge in your septic tank. These can be annoying as they can spread in your house as well. If you notice that you have a lot of insects in your bathroom, you can check if your septic system needs to be pumped again.

It is a great idea to schedule these maintenance services every few months or years. This depends on the size of the tank and how often you use it.

How can you clean a septic tank?

The sludge is pumped out of the septic tank. Companies have special equipment to do this. It is essential that this happens in the right way as removing the wrong layers of sludge can disturb the tank. Don’t use a simple pump to clean it! This can damage the way the tank works and could result in having to clean it more often. Working on a septic tank requires a certain level of expertise if you want to get it right. Make sure that they drain your tank completely, some lazy technicians can leave some residue in it.

Getting a septic tank pumped empty costs about 500 USD.

It is important that the drain field is well maintained. Don’t park vehicles in it and don’t pour liquids in the field. It is also essential that you don’t pour cooking oils into your sink if you have it connected to a septic tank. Things like tampons or wet wipes shouldn’t be flushed either. 

What to do if your septic tank is filling up quickly (after getting it pumped)

Septic tanks should only be full every so often. If your tank is full all the time, it can indicate the following problems:

-Rainwater is seeping into the tank. Check the cover of the tank to make sure that there are no holes around it.

-Groundwater is getting into the tank. Check the connections between the leach field and the floor of the tank.

-There is a problem with the processes in the tank. You can ask a specialist to examine this further.

-You are flushing items that shouldn’t be flushed. This can create problems with the tank as it is not possible to process everything.

-The tank was not properly cleaned. Some companies leave a small residue in the tank but that is not the best way to do it.

The tank is too small. You have to adjust the size based on the number of users.

-The septic system is not properly installed. You need to have the right underground for the leach field. If there are problems, you can consider adding a mound to the leach field.

It is quite expensive to get a tank cleaned and if it is full all the time, there might be a problem. You can ask a builder to check it. They have special cameras that can go into the drains to see if there are problems. Some of these are quite easy to fix. Others will require more work.

To conclude, we can state that there are several ways in which you can determine if your septic tank is full.