305 Gallon Vertical Liquid Storage Tank: Complete Buyer's Guide
At 305 gallons in a stout 50-by-46-inch body, this Norwesco tank is the short, stable small-chemical vessel — barely above waist height, hard to tip, and easy to fill without a step. Its 1.5-specific-gravity wall handles chemicals up to 12.5 pounds per gallon, and the factory siphon outlet draws it nearly empty.
Specifications at a Glance
Every figure below is pulled straight from the live product record for this exact tank — the same data on the product page, so what you read here and what you buy never disagree.
Standards & Materials
- ASTM D1998 — Standard Specification for Polyethylene Upright Storage Tanks. Governs wall-thickness and hydrostatic design for vertical rotomolded poly tanks of this class.
- FDA 21 CFR 177.1520 — Olefin polymers. The food-contact regulation the FDA-grade resin in this tank is compounded to meet.
- Specific gravity rating 1.5 — the tank is engineered for liquids up to 1.5× the density of water (water is about 8.34 lb/gal). Confirm your fluid’s SG before storage.
Product Overview
The 305 Gallon Vertical Liquid Storage Tank takes the opposite approach to the slim 300-gallon column: it sits low and wide, only 50 inches tall on a 46-inch base, so you fill and sample through the 16-inch lid standing flat-footed and the tank stays planted even when half-full and bumped. It is the practical small tank for shops, nurse setups, and chemical pads where a low, steady vessel beats a tall one.
The squat shape buys stability and easy access. With height and width nearly matched, the tank resists tipping and spreads its modest load over 11.5 square feet. Translucent white walls reveal the chemical line through the shell, and the white pigment reflects sun to keep contents cooler outdoors.
Empty it is just 74 pounds — a one- or two-person lift. Filled with a 1.5-SG liquid it reaches about 3,890 pounds, a little under two tons over the broad small base. Low on the tank sits a factory 2-inch siphon-tube outlet for a thorough draw, with the 16-inch lid handling filling and access. There is no factory-installed inlet.
Seamless single-shot molding means no joint to leak, the UV package lives in the resin, and Norwesco's 3-year defect warranty backs it. Each one is checked before it heads out for delivery.
Technical Drawing
Official Norwesco technical drawing — 305 Gallon Vertical Liquid Storage Tank
Key Features and Specifications
- 305-gallon capacity — sized for agricultural chemical and fertilizer storage
- Constructed from virgin linear polyethylene (HDPE) with 1.5 specific gravity rating — handles liquids up to 12.5 lbs/gal
- 50" tall x 46" diameter — compact vertical footprint
- 74 lbs empty, approximately 3,890 lbs when full at rated specific gravity
- 2" fitting with 2" siphon NPT outlet fitting — factory installed and leak-tested
- 16" lid opening for fill, venting, and interior access
- FDA approved for potable water and food-grade liquid contact
- 3 Year Warranty from Norwesco against manufacturing defects
- Translucent white walls allow visual level monitoring without opening the tank and reflect sunlight to keep contents cooler
- Rated for continuous service up to 120 F / 48 C
- Seamless one-piece rotational molding — no seams, no welds, no leak points
- Manufactured by Norwesco — a leading name in rotomolded polyethylene tanks
- Place on a firm, level surface free of rocks or sharp objects that could damage the tank bottom. Ensure adequate ventilation if stored chemicals produce vapors
- Ships via LTL freight on a pallet — residential delivery with lift gate available
Installation and Setup Guide
The 305 is an easy tank to place well precisely because it is low and balanced — but a flat base still matters, and two tons over a small footprint is a real point load on whatever sits beneath it.
Site Preparation
Set it on a firm, flat surface that supports the full 46-inch base — a slab, a paver bed, or a compacted pad. Keep it level within a quarter inch; even a low tank loads one edge if it tilts. Clear away grit and sharp objects so the flat bottom rests cleanly.
Placement and Connections
Aim the 2-inch siphon outlet at your pump and keep the plumbing short. Thread schedule-80 PVC or stainless onto the bulkhead, hand-tighten then strap-wrench-finish, and fit a flex coupling before any hard pipe to absorb expansion. A foot and a half of clearance is plenty to sample and inspect.
Venting
Make sure the lid vent admits air as fast as your pump draws liquid, or the wall will dimple under vacuum. On chemical service, fit a pressure-vacuum relief vent matched to the product.
Maintenance and Long-Term Care
This tank asks very little; a brief quarterly look-over keeps it sound for years.
Quarterly Inspection Checklist
- Shell: Look for any bulge or a flat spot at the base that signals overload or a settled pad.
- Outlet: Feel the 2-inch siphon fitting for weeping and snug it by hand.
- Base: Confirm the surface stays level under the wide small footprint.
- Vent: Keep the lid vent clear so the tank breathes freely both ways.
Cleaning
Drain through the siphon outlet, then rinse the interior with a solution that neutralizes the previous chemical before switching products. Use a spray wand through the 16-inch lid to clean from above. Contain and dispose of the rinse water as specified on the product's SDS.
UV and Weather Protection
With UV protection in the resin it handles the outdoors; inspect the south wall yearly for chalking. A shade or a roof overhang extends the life of any small tank kept in harsh sun.
Alternatives and Comparisons
The 305-gallon size offers a choice of stance. This squat, wide tank is the steady, easy-access pick where floor space allows. A slim 300 stacks the same volume into a narrower base to save floor and build more outlet head. For small batches that need a clean drain, a compact cone-bottom tank clears out more fully than this flat bottom. And for water, the matching black water tank costs less by carrying a lighter 1.1-SG wall than this 1.5-SG chemical build.
Frequently Asked Questions
How long will the 305 Gallon Vertical Liquid Storage Tank last?
A service life of fifteen to twenty years is reasonable if the tank stays at or under 1.5 SG, rests level, and stores compatible products. With no seams and UV protection in the resin, the shell is durable; early failures trace to an overloaded wall, a vent that pulled a vacuum, or chemical attack on incompatible plastic.
What chemicals can I store in this tank?
At 1.5 SG it handles most fertilizers, treatment chemicals, and many acids and bases up to 12.5 pounds per gallon. Those sit safely in polyethylene; strong oxidizers, many solvents, and flammable fuels do not. Cross-reference the chemical on a poly compatibility chart and confirm its weight before filling.
What kind of foundation does a 305-gallon tank need?
A full load is about 3,890 pounds over the 46-inch base. A firm, level slab, paver bed, or compacted pad that supports the full diameter is sufficient. Keep the surface flat within a quarter inch and free of grit under the bottom.
Does this tank come with a warranty?
Yes, three years of Norwesco coverage applies to defects in materials and workmanship such as pinholes and molding flaws. Damage from exceeding 1.5 SG, chemical incompatibility, a bad base, or impact is not covered. Store the receipt and a few photos of the finished job for claim documentation.
Can I install this tank underground?
No. As an above-ground vessel, its flat walls would fail under the pressure of surrounding soil, which also voids the warranty. Below grade calls for an underground cistern with ribbed, reinforced walls built to handle soil pressure.
Buying Considerations
Three things to verify before you order. First, the stance — this low, wide tank is steady and easy to reach, needing 46 inches of width but only about four feet of height. Second, the contents — keep them within the 1.5-SG rating and confirm the product's weight. Third, freight — it ships on a pallet with a lift gate. Call us to arrange delivery.
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