The Chem-Tainer 100 Gallon PE Rectangular Open Top Tank (SKU TC-R183636A) is a 100-gallon polyethylene rectangular open top tank built for accessible bulk water storage, batching, washdown, and any job where a removable lid or fully open working surface matters more than a sealed top. The open top format makes manual filling, dipping, agitation, and cleanout straightforward, and the rectangular footprint uses floor and pad space more efficiently than a round tank of the same capacity.
Will it work for your job?
This is a true 100 gallon open top tank in tough polyethylene. Filled to capacity with water it carries roughly 834 lb, and that full water weight - not the empty tank weight - is the design load your pad, platform, or stand has to be rated for. Build the base flat, level, and continuously supporting the entire bottom; an open top rectangular tank relies on uniform support across its base, and a high or unsupported corner concentrates load and stress. To confirm 100 gallons against your actual draw and refill cycle, run the numbers through our Tank Sizing Calculator or read the Tank Sizing Guide. The technical drawing on this page shows the exact outside dimensions and wall layout - check it against your space before you order.
Sizing and siting the base
Because this tank is open at the top, plan for evaporation, debris, and the need to keep the contents covered or screened if it sits outdoors. Set it on a full-contact concrete pad or a flat platform sized to the footprint in the drawing. If you are pouring a slab, our guide on concrete pad sizing for above-ground polyethylene tanks walks through the ACI framework for getting the support right. For reuse and aggregation setups - grey water, rainwater, or HVAC condensate collection - the open top format suits a quality-banded storage train; see our breakdown of industrial water reuse tank topology. A 100-gallon open top reserve can also serve as a small emergency or fire-water hold; our fire-water reservoir tank design guide covers where polyethylene fits in that stack.
The mistake to avoid
The most common error with a rectangular open top tank is treating it like a pressure or sealed vessel. It is not. Do not seal a fitted lid against internal pressure, do not plumb it for any pressurized service, and do not assume the flat walls behave like a round tank's - rectangular tanks carry hydrostatic load differently and depend on full, level base support to stay true under a head of water. Verify any added bulkhead fittings and the wall thickness against the technical drawing on this page before you drill, and keep the load static and well supported.
This tank ships LTL freight from the Chem-Tainer plant in Merced, California, with freight quoted live to your ZIP - California and West Coast buyers are close to the origin plant, which works in your favor on an LTL lane. Get your freight estimate with our Freight Cost Estimator or call us at 866-418-1777 and we will quote it for you. Questions on fit, base prep, or sizing this 100 gallon rectangular open top tank to your site? Reach out before you buy and we will make sure it is the right call.
