The Chem-Tainer 45 Gallon Open Top Batch Storage Tank is a 20-inch cube of molded polyethylene built for hand-access batching, mixing, and staging where you need to reach into the tank from the top. With a 20 x 20 x 20-inch envelope and a natural white polyethylene wall, this rectangular open top tank holds 45 gallons in a footprint that tucks onto a bench, a pallet corner, or a mixing station without eating floor space.
Will it work for your batch?
The tank carries a 2.0 specific gravity rating, and that number matters more than the gallon count. Filled with plain water the 45 gallons weigh about 375 pounds, and the wall is rated to carry up to roughly 751 pounds of contents — right at twice the water weight (375 x 2 is about 751), so the 2.0 SG rating is internally consistent and gives you real headroom for fluids denser than water. Confirm your fluid's specific gravity before you fill and design around the max rated contents weight, not the gallon number. The open top gives full access for manual charging, scooping, sampling, or dropping in a portable mixer, and the flat 20 x 20-inch base sits stable on a level surface. If you are weighing this size against other capacities, run your volume and fill height through our Tank Sizing Calculator and Tank Sizing Guide before you commit. See the technical drawing on this page for exact dimensions.
Set it on the right base
An open top rectangular tank loaded to 751 pounds needs a flat, continuously supported surface — no spanning across joists or setting on an uneven pad. For a permanent above-ground install, our guide on concrete pad sizing for above-ground polyethylene tanks walks through the support framework. If this tank is one node in a larger reuse or aggregation setup, the industrial water reuse tank topology guide covers how banded storage trains fit together.
The mistake to avoid
Fittings: none — this is an open top batch vessel by design, not an incomplete listing. That makes it a batching and staging tank, not a sealed storage or transfer tank. Do not plan to plumb a bottom outlet into it, and do not leave it uncovered where debris, rain, or contamination can drop in during unattended storage. If you actually need bottom drainage and clean transfer, step up to a fitted, sloped vessel instead — our comparison of Chem-Tainer cone-bottom tanks at 30 vs 45 degrees shows how drainage rate and residual heel change with the cone, so you can pick the right transfer tank rather than modifying this open top.
This tank ships LTL freight, quoted live to your ZIP from the nearest stocking plant — Sheldon, IA or West Babylon, NY. Get an exact number with our Freight Cost Estimator, or call 866-418-1777 and we will quote the rate and confirm the right open top size for your batch process.
