Best Laundry Detergents for Greywater Systems

Greywater systems can cut water waste and support sustainable landscaping—but only if the products you use are safe. The most important factor? Choosing the right laundry detergent.

What Makes a Detergent Greywater-Safe?

Not all eco-friendly products are created equal. When choosing detergent for greywater use, look for:

• Biocompatible (not just biodegradable)
• Low sodium content
• Free from synthetic dyes, fragrances, or softeners
• No chlorine bleach or optical brighteners

Biocompatible detergents go a step beyond biodegradable—they won’t harm soil structure or plant health even with long-term use.

Ingredients to Avoid

When scanning the label, avoid:

• Salt-heavy compounds (any ingredient starting with “sodium”)
• Borates, phosphates, and alkylbenzene
• Brighteners, colorants, synthetic scents
• “Whiteners” or chlorine bleach
• Pods or detergent with plastic coatings

Even some plant-based brands sneak in harsh chemicals. Shorter, simpler ingredient lists are often better.

Greywater-Friendly Detergents to Consider

Here are some of the most reliable options you can find in stores or online:

Oasis Laundry Detergent

• Truly biocompatible
• No sodium compounds
• Formulated specifically for greywater irrigation

ECOS Liquid Laundry Detergent

• Biodegradable and plant-based
• One sodium compound only
• Lightly scented with essential oils

Earth Breeze Laundry Sheets

• Compact and plastic-free
• Low-salt formula ideal for greywater reuse
• Easy to store, no mess

Trader Joe’s Liquid Laundry Detergent

• Low in salts
• No synthetics or dyes
• Natural essential oil scent

7th Generation Free & Clear

• USDA certified biobased
• Low salt levels
• Fragrance-free

Ever Spring (Target brand)

• Clear formula, no dyes
• Moderate salt content
• Budget-friendly greywater option

Detergents to Skip

Avoid brands like Tide, Downy, and Gain. These products typically contain:

• High concentrations of salt
• Artificial ingredients
• Harsh cleaning agents that harm soil

Tips for Using Laundry Detergent with Greywater

• Flush your system with fresh water occasionally to manage salt buildup
• Avoid powdered detergents—liquids or sheets are better
• Skip fabric softeners entirely (or switch to dryer sheets)
• Use cold water cycles to reduce residue

Final Word

Choosing a detergent for greywater irrigation isn’t just about eco-marketing claims. Look past the branding. Read the label. Prioritize biocompatibility and low salt content. With the right laundry soap, your greywater system will stay efficient, safe, and sustainable.