The Chem-Tainer 300 Gallon Horizontal Leg Tank (SKU TC3866LC) is a Natural White polyethylene transport tank built for moving liquid across a field, a yard, or a job site without a permanent foundation. The molded legs hold it stable on a flatbed, a skid, or a trailer deck, and at 73 inches long, 37 inches wide, and 42 inches tall this horizontal tank lays low so the load stays put while you drive. Rated to a specific gravity of 1.5, it handles liquids meaningfully heavier than water, which is the whole point of a 300 gallon leg tank for fertilizer, brine, and similar field chemistries.
Will it work for your load?
Start with weight, because that is what trips people up on a horizontal leg tank. Filled with plain water this 300 gallon tank carries about 2,502 pounds; at its full 1.5 specific-gravity rating the contents can reach roughly 3,753 pounds. That loaded figure - close to 3,750 pounds on your deck - is the real question for a hauler: confirm your trailer, tie-downs, and axle GVWR are rated to carry it loaded before you fill, not after you reach the scale house. Note that the dry tank weight is not listed in our data, so contact us to confirm the empty weight before you finalize trailer payload math. The footprint is 37.0 x 73.0 inches, so plan your deck space and strap points around that horizontal stance. If you are deciding between sizes, run the numbers through the Tank Sizing Calculator or read the Tank Sizing Guide first. For dimensional detail and fitting locations, see the technical drawing on this page.
Chemical compatibility
This tank is molded in polyethylene (resin grade to be confirmed: HDLPE vs XLPE) with a 1.5 specific-gravity rating - confirm the exact resin grade with us before any chemical service, since different resins behave differently against certain chemistries. Within the 1.5 SG rating, this tank suits liquids such as Acetic Acid (60%), Aluminum Sulfate (50%), Calcium Chloride (40%), Ferrous Sulfate (20%), Magnesium Chloride (30%), Sodium Carbonate (30%), Urea Solution (50%), and Ozonated Water (up to 10 PPM). It is also rated for DEF (diesel exhaust fluid) at 32.5% - and DEF is the one to get right: it requires 316SS fittings with EPDM gaskets, not PVC, because DEF purity is sensitive to wetted metals. Most of the other chemistries call for PVC fittings with EPDM gaskets, while Acetic Acid and Urea Solution use PP/PVC fittings with EPDM. Fitting and gasket selection matters as much as the tank wall, so always verify against the Chem-Tainer OEM chemical-resistance chart, which is concentration and temperature specific. See Acetic Acid, Aluminum Sulfate, Calcium Chloride, DEF, Ferrous Sulfate, Magnesium Chloride, Sodium Carbonate, and Urea Solution, plus our full chemical compatibility reference.
Heavier chemistries need a higher-SG tank
The decision rule is simple: a denser, more aggressive chemistry needs the 1.9 specific-gravity tank, not this 1.5 SG version - and several of those need Viton or Aflas gaskets with CPVC or 316SS fittings, not the EPDM/PVC default. That covers common water-treatment and industrial chemistries like Sodium Hypochlorite (bleach), Sulfuric Acid, Hydrochloric Acid, Ferric Chloride, Hydrogen Peroxide, Phosphoric Acid, Ethylene Glycol, Ferric Sulfate, Hydrofluoric Acid, Hydrofluosilicic Acid, Peracetic Acid, Polyaluminum Chloride, Potassium Carbonate, Potassium Hydroxide, Propylene Glycol, Sodium Bisulfate, Sodium Bisulfite, Sodium Thiosulfate, and Zinc Orthophosphate. If your service is on that list, do not put it in this 1.5 SG tank - ask us about the 1.9 SG version and the correct fitting and gasket pairing. And if you are sizing a horizontal leg tank into a non-roadable trailer or applicator setup, the DOT scope is worth reading first: our guides on applicator and leg tanks for fertilizer and portable utility tank DOT classification cover it, and if you are blending fertilizer the tank stratification guide is worth your time.
This tank ships LTL from the Merced, California plant, with freight quoted live to your ZIP - get your number from the Freight Cost Estimator or call 866-418-1777. Because it is a horizontal leg tank, palletizing and the loaded weight both factor into the freight class, so estimate before you commit. Listed before freight; call us with your delivery ZIP and your chemistry and we will confirm the right tank, SG rating, and fittings for the job.
