165 Gallon Plastic Water Storage Tank: Complete Buyer's Guide
165-gallon black water storage tank built for safe potable water storage. Manufactured by Norwesco from virgin linear polyethylene (HDPE) rated to handle liquids up to 9.2 pounds per gallon. FDA approved for contact with potable water, ensuring safe storage for drinking water and food-grade liquids.
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 1.1 — the tank is engineered for liquids up to 1.1× the density of water (water is about 8.34 lb/gal). Confirm your fluid’s SG before storage.
Product Overview
The 165 Gallon Plastic Water Storage Tank is a compact upright tank for the jobs that fall between a portable jug and a bulk reservoir. A hundred and sixty-five gallons is enough to water a flock, feed a drip system, supply a workshop sink, or hold an emergency household reserve, all in a 31-inch-wide footprint that fits a closet, a trailer corner, or a narrow utility space.
It is rotationally molded by Norwesco in one seamless piece of virgin linear polyethylene, rated to 1.1 specific gravity for water-based liquids up to 9.2 pounds per gallon, with a 120 F / 48 C ceiling. The black pigment blocks light to suppress algae and gives the wall its strongest UV resistance, so the tank holds up whether it lives indoors or out in the weather.
At 56 inches tall and 31 inches across, it weighs only 44 pounds empty — easy for one person to carry and position — and about 1,558 pounds full at 1.1 SG. A factory 2-inch NPT outlet feeds your line, and the 16-inch lid is generous for a tank this size, opening wide for filling and cleaning. Norwesco's 3-year warranty against manufacturing defects applies.
Technical Drawing
Official Norwesco technical drawing — 165 Gallon Plastic Water Storage Tank
Key Features and Specifications
- 165-gallon capacity — sized for safe potable water storage
- Constructed from virgin linear polyethylene (HDPE) with 1.1 specific gravity rating — handles liquids up to 9.2 lbs/gal
- 56" tall x 31" diameter — compact vertical footprint
- 44 lbs empty, approximately 1,558 lbs when full at rated specific gravity
- 2 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
- UV-resistant black pigmentation provides maximum outdoor durability and inhibits algae growth in stored liquids
- 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 is the rare water tank one person can install unaided. Empty, at 44 pounds, you carry it into place; the work is all in giving it a sound base so the roughly 1,558 pounds of a full tank press evenly on the bottom.
Base
The tank wants a firm, level surface free of anything sharp. Indoors, a swept concrete floor is ideal. Outdoors, a small slab or a compacted, drained pad works. With only a 31-inch diameter the base is easy to true, but check it with a level in two directions — a tall, narrow tank tips its water line noticeably if the floor slopes, and an uneven bottom presses stress into the wall.
Connections
Plumb the 2-inch outlet to your draw line, and if you fill from the top through the 16-inch lid, a simple float valve keeps it from overflowing. There is no separate inlet fitting on this size, so a top fill or a tee off the outlet is the usual approach. Keep the first foot of the outlet line flexible to absorb wall movement, and add a shutoff valve for easy isolation.
Venting
Whenever the tank is plumbed closed, fit a screened vent in the lid so air replaces the water you draw. A small tank can still pull a vacuum and dent if a pump empties it faster than air can enter, so size the breather to your draw and keep the screen clear to protect the water.
Maintenance and Long-Term Care
A small potable tank is the easiest of all to keep clean, precisely because its modest volume turns over quickly and its low weight makes draining and refilling a five-minute job.
Quick Checks
- Wall and fittings: Eyeball the wall for any bulge and the 2-inch outlet for weeping every few months, and hand-snug the fitting if it has loosened.
- Lid and screen: Confirm the 16-inch lid seats fully and the vent screen is intact, so nothing reaches the stored water.
- Base: Make sure the tank still sits level and has not crept on its pad.
Sanitizing
Because the volume is small, you can refresh this tank often. Drain and flush the floor, then disinfect with the potable dose of a quarter cup of unscented bleach per fifteen gallons, hold the filled tank two hours, and rinse until the chlorine smell clears. For an emergency-reserve tank that sits unused, run this cycle at least once a year and rotate the stored water periodically so it stays fresh.
Indoor and Outdoor Use
Kept indoors, the tank sees no UV and effectively never ages from sunlight. Outdoors, the black pigment and resin UV package carry it for years; an occasional look at the sun-facing side is all the attention it needs. In freezing conditions, a small tank can ice quickly, so drain it or keep it warm if winters are hard.
Alternatives and Comparisons
At 165 gallons the question is usually how much reserve you actually need and how little space you can spare for it.
Stepping up or down: This tank's narrow 31-inch upright body is built to fit where a wider tank cannot. If you need more buffer and have the floor for it, a 220- or 300-gallon tank steps up without a huge footprint increase; if 165 gallons is more than your space allows, a smaller upright drops in further. Compared with stacking portable jugs, a single 165-gallon tank gives you a plumbed, sealed, light-blocked supply that does not need refilling by hand.
Other 165-Gallon Options
Frequently Asked Questions
How long will the 165 Gallon Plastic Water Storage Tank last?
With a level base and use within its 1.1 SG and 120 F ratings, this tank gives 15 to 20 years and often more, since small tanks lead an easy life. The black UV-loaded wall resists sun whether the tank is indoors or out, and the one-piece molded body has no seam to fail. Periodic draining and sanitizing keeps the water fresh over that span.
What chemicals can I store in this tank?
It is an FDA-approved potable-water tank, suited to drinking water, livestock, irrigation, and emergency reserve, plus water-based liquids within its 1.1 specific-gravity rating. It is not for fuels, solvents, or harsh chemistry; a 1.5-SG liquid tank with a verified compatibility check is the right choice there.
What kind of foundation does a 165-gallon tank need?
A full 165-gallon tank weighs about 1,558 pounds — light enough for a swept concrete floor indoors or a small compacted pad outdoors, with no engineered foundation. Just keep the surface flat and free of sharp objects so the bottom is evenly supported.
Does this tank come with a warranty?
Yes. Norwesco's 3-year warranty covers manufacturing defects in materials and workmanship under normal use — molded-in faults, not damage from a poor base, overfilling, incompatible chemicals, or impact. Keep your receipt for any claim.
Can I install this tank underground?
No. The upright wall is not engineered to resist soil pressure, so burying this tank would risk collapse and void the warranty. For below-grade storage, choose one of our reinforced underground cisterns.
Buying Considerations
Three quick points before this 165-gallon tank ships. First, access: at 31 inches wide it fits most doorways and tight spaces, but measure your path if it is going indoors. Second, fittings — it comes with the 2-inch outlet; plan a top fill through the lid or a tee, since there is no separate inlet at this size. Third, delivery: at 44 pounds empty it ships easily on a pallet and one person can handle it on arrival. Listed at $450.00 before freight, quoted to your ZIP.
Related Products You May Need
Questions? Call (866) 418-1777 — our team knows these products inside and out and can help you select the right tank for your application.
Recommended Tanks for This Guide
Live pricing, updated automatically · estimate freight to your ZIP.
