The Chem-Tainer 185 Gallon PE Rectangular Open Top Tank is a polyethylene rectangular open-top vessel built for above-ground water storage, batch mixing, washdown staging, and any job where you need to dip, scoop, or top-fill from above rather than work through a closed lid. At 185 gallons of rated capacity in a rectangular footprint, it fits tight against walls and into corners where a round tank wastes floor space, which is exactly why open top tank and rectangular open top tank are the searches that lead people here.
Will it work for my job?
This is an open top configuration, so you get full access to the interior from above for cleaning, manual filling, agitation, or pulling water by bucket or pump. The body is molded polyethylene, the standard material for above-ground water storage because it does not corrode or rust the way steel does. Plan around weight before plumbing or mounting anything: filled with water to capacity, this tank carries roughly 1,543 pounds. That load sits entirely on whatever surface you set it on, so the pad or platform underneath has to be flat, continuous, and rated for it. If you are not sure how 185 gallons maps to your actual demand, run the numbers with our Tank Sizing Calculator and the Tank Sizing Guide before you commit to a footprint. For rural or remote water staging, including private fire-protection reserves, our fire-water reservoir tank design guide works through NFPA 22 sizing and the freeze-protection engineering that matters once an open surface meets cold weather.
Setting it on the right base
An open top rectangular tank distributes its weight across a flat bottom, but a 1,543-pound filled load still demands a properly sized foundation. A poured pad keeps the base level and prevents the bottom from flexing or settling unevenly over time, which is the most common avoidable problem with above-ground polyethylene storage. Our guide on concrete pad sizing for above-ground polyethylene tanks walks through the ACI framework for sizing that base correctly. If this tank is part of a water reuse or aggregation setup, the industrial water reuse tank topology guide covers how open-top vessels fit into grey-water, rainwater, and condensate trains.
The mistake to avoid
The most common error with an open top tank is treating "open top" as "vented and weatherproof." It is neither by default. Anything that falls from above goes straight into your water, an exposed surface invites debris, sunlight, and evaporation, and in cold climates a standing open surface will ice over before a closed tank does, so site it under cover, fit your own lid, or plan freeze protection if the water has to stay clean and usable year-round. Confirm the exact outside dimensions and internal depth against the technical drawing on this page before you build the enclosure or pad around it, because a rectangular footprint only saves you space if the opening clears your fill and access points. One more thing worth checking up front: this is a top-access vessel, not a gravity-drain tank. If the job actually needs clean self-draining with a low residual heel, compare a sloped design using our Chem-Tainer cone-bottom 30 vs 45 drainage comparison instead.
This tank ships LTL freight, quoted live to your ZIP from the nearest stocking plant. It ships from Hummelstown, Pennsylvania, with West Babylon, New York as a secondary point, and we quote from whichever plant gives you the shorter lane, so PA tends to win for Mid-Atlantic and inland buyers while NY runs shorter for coastal New England. Get a freight quote in seconds with our Freight Cost Estimator, or call 866-418-1777 and we will quote it for you and confirm the right tank for your application.
