What Kind Of Laundry Detergent Is Best For Septic Tanks

If you have a septic tank, you might be considering which is the best type of laundry detergent to ensure you are not straining your septic tank.

Water from your laundry machine makes up the majority of the water in your septic tank.

It is essential to know what type of laundry detergent you need to use not to harm your septic tank.

You need to consider several factors when determining which laundry detergent is best for your septic tank to avoid health and environmental hazards and septic tank maintenance.

While there are countless laundry detergents on the market to choose from, we’ve narrowed it down to our top 8 choices.

Continue reading below to find out what kind of laundry detergent is best for septic tanks.

Laundry Detergents In This Review

What Makes A Good Septic Tank Safe Laundry Detergent

When shopping for laundry detergent that is septic tank safe, there are several different contributing factors you will need to review.

The type of laundry detergent, whether liquid, powder, or homemade, the level of surfactants, and the presence or lack of biodegradable ingredients will be part of the consideration as to which will break down better in the tank and extend the life of your septic tank.

Powder vs. Liquid vs. DIY

First, you need to consider which type of laundry detergent you should use between powder, liquid, or DIY, or homemade laundry detergent.

Generally, liquid laundry detergent is recognized as the best of these types.

One of the most significant issues with laundry detergent in the septic tank is clogging and accumulation. 

Liquid laundry detergent will dissolve completely and not clog the septic tank.

On the other hand powder, laundry detergent may be more likely to cause clogs as the powder has particles that do not fully break down, and they will settle in the septic tank. 

Another consideration is if you want to make your own homemade laundry detergent.

Homemade powder laundry detergents may even be better for septic systems than commercial powder laundry detergents; this is because DIY ingredients in laundry detergents often avoid filler substances, and components, such as baking soda, do not create too many suds. 

If you want to read a more in-depth article about the differences between liquid and solid detergents, check out our related article on which is better, liquid or powder detergents.

Surfactant Levels

Surfactants are chemicals that are present in most laundry detergents.

These chemicals work to lift and remove dirt from the fabric in your clothes.

Although surfactants can be very important for your stained clothing, too high levels of surfactants can be detrimental to your septic tank.

If you have a septic tank, you will want to find a laundry detergent with lower surfactant levels.

Surfactants are not always processed in septic tanks, which can then cause contamination of groundwater and surface water. 

Some laundry detergents boast natural surfactants, and these can be a better alternative that allows your laundry detergent to remove dirt while also breaking down better in your septic tank.

If you’re interested in natural laundry detergents, check out our related article on how to make natural laundry detergent.

Natural surfactants generally come from plant oils, such as coconut oil in coco betaine and sodium lauryl sulfate.

These surfactants will still suds up but not be more likely to biodegrade in the septic tank; bonus, they are natural!

Biodegradable Detergents

By nature of a septic tank, decomposition happens to all the liquid and solid waste being sent to the septic tank.

Biodegradable ingredients are much better for septic systems.

Not only do biodegradable detergents more effectively and efficiently break down, but they also help to feed the bacteria and natural microorganisms inside the septic tank. 

Looking for detergents that contain more biodegradable ingredients is, in the end, going to be much more beneficial to your septic tank in the long run.

With more components in your laundry detergent decomposing, it will lead to less build-up and particle settlement at the bottom of your septic tank.

In addition, these ingredients are not going to lead to any hazards in ground and surface water as with other elements in laundry detergent.

Reviews Of The Best Laundry Detergents For Septic Tanks

In this section, we’ll discuss each of our picks for the best laundry detergent for septic tanks.

#1 Arm & Hammer Plus OxiClean

Arm & Hammer provides a septic-safe liquid laundry detergent with biodegradable ingredients, including its surfactants, different enzymes to help with septic tank decomposition, and other elements which will not lead to the build-up, which will shorten the life of your septic tank.

Arm & Hammer is a familiar household brand, which means it will not be as expensive as other septic safe laundry detergents.

If you want your detergent to be scented, this Arm & Hammer Plus OxiClean comes in a Fresh Burst scent.


  • Liquid detergent 
  • Biodegradable ingredients

#2 Seventh Generation Natural Concentrated Laundry Detergent 

Another laundry detergent that will save you money and septic tank by using less detergent is Seventh Generation Natural Concentrated Laundry Detergent.

This detergent has plant-based ingredients and enzymes that will allow for better decomposition in your septic tank, leading to fewer clogs and build-up in your septic tank. 

While it is concentrated and you do not need to use it as much, Seventh Generation Natural Concentrated Laundry Detergent does come with a higher price tag.

It is scentless as well as hypoallergenic, which makes it an excellent option for those who have allergies or prefer no scent in their laundry detergent.

If you do find yourself with an allergic reaction to certain laundry detergents, check out our article on how to get rid of an allergic reaction to laundry detergent.


  • Concentrated
  • Liquid Detergent
  • Plant-based ingredients

#3 Mrs. Meyers Clean Day Laundry Detergent 

Mrs. Meyers Clean Day Laundry Detergent is a concentrated detergent that allows you to use much less detergent, which is better in the end for your septic tank.

Less detergent = fewer problems!

The ingredients are biodegradable, which will break down easier and more quickly in your septic tank. 

The natural ingredients of Mrs. Meyers laundry detergent do come at a price.

It is more expensive than your average laundry detergent.

Consider, however, that it is concentrated, so you do not need to use as much, and it will last longer than other detergents as long as you follow the label.

Mrs. Meyers also comes in a variety of scents, such as lavender, baby blossom, basil, honeysuckle, and lemon verbena.


  • Concentrated
  • Liquid Detergent
  • Plant-based ingredients

#4 Dropps Laundry Detergent Pods

Dropps Laundry Detergent Pods are made from plant-based ingredients allowing for better decomposition rates in your septic tank.

Although in pod form, these are still made of liquid laundry detergent, which allows for the better dissolving of the ingredients in your septic tank. 

Dropps Laundry Detergent Pods come in both scented and unscented varieties, depending on your household’s preferences.

In addition, the recyclable and compostable packaging creates a smaller carbon footprint, avoiding large plastic containers that are often just sent to the landfill. 


  • Pods
  • Liquid detergent
  • Plant-based ingredients

#5 ECOS Liquid Laundry Detergent 

ECOS laundry detergent is made from plant ingredients and is biodegradable.

This makes it a good option for your septic tank, avoiding build-up and settling of ingredients that might not biodegrade or do so slowly. 

ECOS comes in several different types of scents that are all hypoallergenic, as well as unscented options. It also has a line of baby laundry detergent as well! ECOS is free of any irritants that might cause irritation on the skin, making it an excellent choice for anyone with sensitive skin.


  • Liquid detergent
  • Biodegradable ingredients

#6 Charlie’s Soap Fragrance-Free Laundry Powder 

Charlie’s Soap Laundry Powder detergent is a great option if you decide on the powder detergent route.

Even though powder detergents are not always the best avenue for a septic tank, the ingredients in Charlie’s Soap Laundry Powder will not cause clogs due to low surfactant levels avoiding suds and biodegradable ingredients that will not settle in the septic tank.

A bag of Charlie’s Soap Laundry Powder will last a longer amount of time than a container of liquid laundry detergent, as the liquid detergent contains water already.

It also is fragrance-free, which is a plus for those who prefer no scent or have sensitive skin and allergies.


  • Powder Detergent
  • Biodegradable ingredients

#7 Biokleen Free & Clear Laundry Powder

Biokleen’s ingredients are plant-based and are free of any chemicals that will clog up your septic tank. 

The formula of Biokleen’s Laundry Powder is unscented, which is good for customers who want to avoid scents.

Biokleen also carries a liquid variety if a customer still wants a similar formula from Biokleen, but in a different form. 


  • Concentrated
  • Powder Detergent
  • Plant-based ingredients

#8 Dr. Bronner’s Pure-Castile Liquid Soap 

Dr. Bronner’s Pure-Castile Liquid Soap can be used as a liquid laundry detergent that is safe for your septic tank with natural ingredients from plants.

It is very concentrated, which allows you to use much less, leading to fewer chemicals in your septic tank.


  • Liquid detergent
  • Organic ingredients
  • Concentrated 
  • Can be used for other cleaning purposes

Commonly Asked Questions About Safe Laundry Detergent For Septic Tanks

What do I do if I haven’t been using septic-safe laundry detergents?

If you have been doing this for an extended amount of time, you may speak with a professional to see what they may recommend you do to mitigate any possible damage done to the septic system.

You may also dry to flush dry yeast down a toilet, preferably the one closest to the septic tank, to add good bacteria to aid your septic tank in breaking down the build-up.

What ingredients should I avoid when looking for septic-safe cleaning products?

Different ingredients can harm the bacteria within your septic tank or even just cause build-up in the tank.

Avoid using too much bleach as it might harm the system’s decomposition but also affect the groundwater.

Also, avoid products that have methylisothiazolinone, which is a preservative that may be toxic and will leech into the groundwater. 

Final Thoughts

I hope this was helpful in assisting you to determine what kind of laundry detergent is best for septic tanks.

While Arm & Hammer Plus OxiClean comes out at number 1, all of these laundry detergents are great options for use if you have a septic tank.

You need to determine the needs and wants of your own household.

Do you have a preference for scented or unscented?

Is cost a large determining criterion?

Do you have a preference for eco-friendly packaging and ingredients?

Using this article can help you narrow down based on the needs of your household.