300 Gallon Doorway Water Tank - White (25" x 65"): Complete Buyer's Guide
The 300-gallon doorway water tank (white, 25" x 65") is a slim, tall narrow-access water tank — just 25 inches wide and 65 inches tall on a 59-inch length. Its extra-narrow profile clears even tight door openings while holding 300 gallons of FDA-compliant potable water in a footprint barely two feet across.
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
This is the slimmer, taller take on 300-gallon doorway storage. Where the wider 300-gallon doorway tank is low and squat, this version is just 25 inches wide and stands 65 inches tall — a profile chosen for the tightest openings and narrowest floor spots. If you have a particularly narrow door, a slim alcove, or a wall niche where even a 29-inch tank won't go, the 25-inch width here is what makes the install possible. It packs the same 300 gallons by going taller and narrower.
Norwesco rotomolds it as a single seamless piece of virgin linear polyethylene with FDA-compliant resin for potable and food-grade contact — no joint to leak, no crevice to harbor biofilm. The wall is rated to a 1.5 specific gravity, giving generous structural margin over water. The translucent white wall lets you read the level by eye, and the tall slim shape makes the level especially easy to gauge since each gallon moves it noticeably.
The tradeoff of the slim-and-tall geometry is a higher center of gravity when full, so a stable, level base matters more here than on the squat version. Empty, the tank weighs 129 pounds — two people can maneuver it through a narrow opening. Filled with water it carries roughly 3,882 pounds on its 59-by-25-inch footprint, concentrated on a narrow base, which the supporting floor must be rated to handle. Maximum service temperature is 120°F.
The outlet is a 1.25-inch NPT fitting, factory-installed and leak-tested, with a 16-inch lid for fill, vent, and inspection. Norwesco's 3-year warranty applies, and the tank ships LTL freight on a pallet, with residential delivery and liftgate available.
Technical Drawing
Official Norwesco technical drawing — 300 Gallon Doorway Water Tank - White (25" x 65")
Key Features and Specifications
- 300-gallon capacity — sized for tight-access indoor liquid storage
- Constructed from virgin linear polyethylene (HDPE) with 1.5 specific gravity rating — handles liquids up to 12.5 lbs/gal
- 59" long x 25" wide x 65" tall
- 129 lbs empty, approximately 3,882 lbs when full at rated specific gravity
- 1.25 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
This slim doorway tank's install plays to its strength — squeezing through tight openings — while asking a little extra care on the base, since a tall narrow tank is less forgiving of an unlevel floor than a squat one.
Getting It In and Floor Loading
The 25-inch width is the headline: it clears narrow doors and tight passages that a wider tank can't. Check the 65-inch height and 59-inch length against your route too — you may need to keep it upright through low passages or tip it for others. Two people handle the 129-pound empty tank. Confirm the floor carries roughly 3,882 pounds full, noting that on this slim footprint the weight is concentrated on a narrow base, so even, level support is especially important.
Placement and Connections
Set the tank on a flat, level surface with full contact under the narrow base — a tall slim tank on an uneven floor will lean and load one side, so take the extra minute to get it level. Connect your fill line and the 1.25-inch outlet, using a flexible coupling to absorb thermal movement, and route an overflow so any escaping water drains safely. Position it against a wall for added stability if the spot allows.
Venting
Fit a screened vent in the 16-inch lid sized to your fill and draw rate. A tall narrow tank is a bit more prone to distortion under vacuum, so don't let it draw against a sealed lid. The screen keeps debris and insects out of the potable water, and indoors you should ensure the vent reaches adequate air in an enclosed space.
Maintenance and Long-Term Care
Maintenance is the standard indoor-water routine, with a little extra attention to the tank staying plumb given its tall, slim build.
Quarterly Inspection Checklist
- Plumb and base: Confirm the tall tank still stands straight and the narrow base hasn't shifted — a developing lean on a slim tank means the base needs re-leveling before it worsens.
- Water clarity: Read level and clarity through the translucent wall; indoors, cloudiness usually means the water needs refreshing.
- Fitting and floor: Inspect the 1.25-inch outlet for weeping and confirm the floor under the narrow footprint stays dry and sound.
- Vent screen: Verify the vent is clear and the screen intact.
Cleaning and Sanitizing
Sanitize at least annually, more often if the water sits a long time. Drain, scrub the interior through the 16-inch lid, then disinfect with a chlorine solution — about a quarter cup of unscented household bleach per 15 gallons used — let it stand a couple of hours, drain, and flush with fresh water until no chlorine odor remains. The tall shape drains well, helping you empty it completely for cleaning.
Indoor Considerations
Spared UV indoors, the tank won't chalk. Keep the space within the 120°F limit and protect against freezing in unheated areas. Because it's tall and slim, securing it against a wall or in a niche adds stability and reduces any tip risk in a high-traffic space. Plan drainage around the tank for leak protection.
Alternatives and Comparisons
Two 300-gallon doorway tanks exist for different spaces, so choose by your spot:
This slim 25"-wide version versus the wider 29" doorway tank: the 25-inch tank fits tighter openings and narrower floor spots but stands taller, with a higher center of gravity; the 29-inch version is lower and more stable but needs more width and floor area. Measure your actual opening and floor footprint — whichever fits is the right one, and they hold the same 300 gallons.
Doorway versus standard tank: as always, the doorway format is for access-constrained spaces; a standard cylinder is cheaper per gallon where you have room. The slim profile here buys access into the tightest spots.
Other 300-Gallon Options
Frequently Asked Questions
How long will the 300 Gallon Doorway Water Tank - White (25" x 65") last?
Fifteen to twenty years is realistic, with indoor placement removing UV and weather to favor the upper end. The one care point specific to this tall slim tank is keeping it level — a chronic lean stresses one side — so a level base plus routine sanitizing gets the seamless wall to a long service life.
What chemicals can I store in this tank?
This is a potable water tank — FDA compliant for drinking water and food-grade liquids and rated to a 1.5 specific gravity, giving ample structural margin for water and benign aqueous solutions. Doorway tanks are intended for water and water-based storage; never use one for fuels, solvents, or flammables, and confirm compatibility before storing any chemical.
What kind of foundation does a 300-gallon tank need?
A full tank is roughly 3,882 pounds on the slim 59-by-25-inch footprint. Most floors carry that, but because the weight sits on a narrow base, even, level support is especially important — verify a questionable floor before filling. A flat, level surface free of debris is the requirement.
Does this tank come with a warranty?
Yes — Norwesco's 3-year warranty covers defects in materials and workmanship. It excludes uneven or improper installation (a particular caution on a tall slim tank), freezing damage, and impact damage. Keep documentation of a level install for any claim.
Can I install this tank underground?
No — this is an above-ground tank designed for interior placement, not burial; soil pressure would deform the wall. For below-grade water storage, use a purpose-built underground cistern designed for soil load.
Buying Considerations
Choose this 25-inch-wide version when your opening or floor spot is too narrow for a wider doorway tank — the slim profile is its whole reason to exist. Measure your route against the 25-inch width, 65-inch height, and 59-inch length; confirm the floor carries roughly 3,882 pounds on the narrow footprint; and plan a genuinely level base plus, ideally, a wall to set it against for stability. Add freeze protection if the space is unheated. It ships LTL on a pallet with residential and liftgate delivery available.
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