The Chem-Tainer 360 Gallon PE Rectangular Open Top Tank is a polyethylene open-top vessel built for straightforward bulk water holding, batching, and gravity-feed staging where you need wide top access and a stable rectangular footprint that sits flush against walls and inside containment areas. At 360 gallons, it gives you a practical mid-size reservoir for rainwater capture, water reuse staging, mixing, washdown supply, and rural fire-water storage without the round footprint of a vertical tank eating up usable floor space.
Will this open top tank work for your application?
This is a rectangular open top tank molded in polyethylene, so it handles water and similar low-specific-gravity liquids well, and the open top makes it easy to fill, inspect, clean, and dip-measure by hand. Filled to its 360-gallon capacity, plan around a full water weight of roughly 3,002 pounds, so the pad or platform under it has to carry that load across the full rectangular base, not just at the corners. This open-top configuration and the listed capacity are rated for water-weight loading (about 3,002 lb full); for liquids heavier than water (specific gravity above 1.0), confirm the wall and heel rating before use, because open-top rectangular geometry is the least forgiving of over-SG loading. Because this is an open-top design, it is not a sealed pressure or fully enclosed storage tank, and it should be sited where overflow, evaporation, and debris exposure are acceptable or managed with a separate cover. To confirm the right volume for your draw-down and refill cycle, run the numbers through our Tank Sizing Calculator or read the Tank Sizing Guide.
Fittings and what ships in the box
This open-top tank ships with no factory-installed fittings, outlets, or gaskets; any drain or bulkhead fitting is field-installed to suit your plumbing. That keeps the configuration flexible, but it means you should plan the outlet location, fitting material, and gasket selection as part of your install rather than expecting a pre-cut port. Refer to the technical drawing on this page for the exact dimensions and base footprint before you lay out any penetrations or pour a pad.
Mounting, siting, and the mistake to avoid
The single most common mistake with a rectangular open top tank this size is underbuilding the support. Water at 360 gallons is over 3,000 pounds, and a rectangular tank distributes that weight differently than a round one, so it needs a flat, fully supporting, continuously bearing surface. A poured pad is the safe answer for a permanent install. If you are placing this above grade or on a structure, size the slab properly first using the framework in our guide on concrete pad sizing for above-ground polyethylene tanks. For cold-climate or standby reservoirs, plan freeze protection up front, and if this is part of a private fire-protection setup, the design discipline in our fire-water reservoir tank design guide will keep your sizing and freeze planning honest. Buyers staging grey-water, rainwater, or HVAC condensate should also see our industrial water reuse tank topology guide for how an open-top rectangular tank fits into a quality-banded storage train.
Freight and how to order
This tank ships LTL freight from West Babylon, New York, and freight is quoted live to your ZIP code rather than included in the list price. Get an exact number for your delivery address with our Freight Cost Estimator, or call 866-418-1777 and we will work out the best routing for a rectangular open top tank of this size. The further you are from the New York shipping point, the more it pays to confirm freight before you commit, so estimate first and order with confidence.
