PolyJohn 300 Gallon Holding Tank

PolyJohn’s 300-Gallon Holding Tank is our largest capacity tank and a vital solution for long-term portable restroom rentals, such as outdoor rest areas or multi-day events. Designed to be functional, discreet, and safe, it provides peace of mind to workers and guests alike.

Constructed from highly durable plastic with thick, heavy-duty walls, the tank is built for long-lasting performance. It features multiple ports to support a variety of plumbing configurations and can be quickly installed using rubber couplers and clamps. The tank is available in a natural color option, allowing fluid levels to be easily monitored from a distance, which is required in some states.

When indoor plumbing is unavailable and bulk waste storage is essential, a holding tank becomes indispensable. The 300-Gallon Holding Tank is perfect for placement under job site trailers, RVs, emergency relief camps, or anywhere reliable, high-capacity outdoor waste storage is needed.

Typical lead times are approximately 2–3 weeks plus shipping.

Features

• Heavy-duty thick-wall construction, ideal for bulk waste storage under trailers or at job sites
• No threaded or cemented joints; compatible with Fernco® rubber couplers and clamps
• Natural color option reveals fluid levels at a glance (required in certain states)

Advantages Over Alternatives

• Discreet appearance
• Extremely durable construction
• Compatible with a variety of plumbing setups

300 Gallon Holding Tank Instructions