The Chem-Tainer 135 Gallon PE Rectangular Open Top Tank is a polyethylene rectangular open-top tank built for batching, mixing, washdown, and bulk water staging where you need full top access to the contents. The rectangular footprint uses floor space more efficiently than a round tank in tight or linear layouts, fits cleanly against a wall or inside a containment curb, and the open top lets you fill from above, stir, drop in a pump or float, and check levels by eye without unthreading a lid.
Will it work for your job?
This is a water-service tank, and the math that matters most is weight. Filled to 135 gallons of water, plan for roughly 1,126 lbs of static load on the pad or platform beneath it. That number drives everything: the pad has to be flat and fully supporting under the entire base, and any stand or mezzanine has to be rated well above that figure with a safety margin. Because the top is open, this tank is sized for atmospheric storage and open-batch work, not pressurized or fully sealed applications. If you are matching a tank to a known daily draw or a specific process volume, run the numbers through our Tank Sizing Calculator and cross-check against the Tank Sizing Guide before you commit. The technical drawing on this page gives you the exact rectangular dimensions so you can confirm it clears your bay, doorway, or containment area.
Fittings and outlets
This is an open-top tank and it ships with no factory outlet. If you need bottom draw, plan to field-install your own bulkhead fitting and gasket sized to your line; if you are running it as a gravity or pump-fed open reservoir, no plumbing is required at all. Knowing this up front means you can order the right bulkhead and gasket alongside the tank rather than discovering the need after delivery.
Common uses and search terms
Buyers reach this tank looking for an open top tank, an open tank, or a rectangular open top tank because the rectangular form ganged in a row beats a round tank for water reuse staging, equipment washdown reservoirs, and grey-water or rainwater aggregation. If you are building a reuse train, the industrial water reuse tank topology guide walks through how to band storage by quality and sequence treatment stages. As an atmospheric reservoir, it also works as draft-source or staging storage for rural and remote fire-water systems; the fire-water reservoir design guide covers NFPA 22 sizing discipline and freeze protection for cold-climate service.
The mistake to avoid: support the full base
The most common error with an open rectangular polyethylene tank is under-building the foundation. Over 1,100 lbs of water concentrated in a flat-bottomed rectangular shell needs uniform, continuous support across the entire base, not point loads or an uneven slab. If you are pouring or specifying a pad, the concrete pad sizing guide covers the ACI 360R-10 framework for above-ground polyethylene tanks. Set it level, support the full base, and keep the load math honest.
This tank ships LTL freight, quoted live to your ZIP from the nearest of two stocking plants, Merced, CA or West Babylon, NY, so coast-to-coast buyers get a shorter LTL lane. Get an exact rate before you order with our Freight Cost Estimator, or call us at 866-418-1777 and we will quote it for you and help confirm this is the right tank for your application.
