175 Gallon Plastic Water Storage Tank: Complete Buyer's Guide
A 175-gallon black water tank from Norwesco, a compact 30-inch column in seamless FDA-grade polyethylene with twin 2-inch ports — the easy step up from a 150.
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 175-gallon Norwesco is the natural step up from the 150 when you want noticeably more reserve without going to a yard-scale tank. It stands 64 inches tall on a 30-inch diameter — a compact column that still slips through most spaces — and weighs just 48 pounds empty, so it is easy to set before the first fill. Full, it carries about 1,653 pounds, well within what a sound floor or simple pad will hold.
The shell is one seamless rotomolding of virgin linear polyethylene with UV black pigment in the resin, blocking the sunlight that turns stored water green. Rated to 1.1 specific gravity it holds water and light compatible liquids to 9.2 pounds per gallon, and it carries FDA approval for potable and food-grade use.
Like the 100-gallon column, this tank carries twin 2-inch NPT ports — an outlet at the base and an inlet up top — both factory-installed and leak-tested, which lets you fill and draw quickly for the size. The 8-inch lid suits the slim diameter and opens the top for fill and inspection. Norwesco's 3-year warranty applies.
Key Features and Specifications
- 175-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
- 64" tall x 30" diameter — compact vertical footprint
- 48 lbs empty, approximately 1,653 lbs when full at rated specific gravity
- 2 NPT outlet fitting — factory installed and leak-tested
- 2 NPT inlet fitting included
- 8" 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
At 64 inches tall on a 30-inch base, the 175 is a stable little column that asks only for a flat place to stand. The setup is quick; the one thing to get right is even support under the whole bottom.
Site Preparation
A level gravel pad or a flat concrete floor carries this tank easily — full weight is well under a ton. The point is not load capacity but flatness: the entire 30-inch base should sit in full contact, with nothing propping one side. Sweep the area clean of grit before setting the tank down.
Placement and Connections
A foot of clearance around the tank is enough for service. The twin 2-inch ports give you room for a proper fill line into the top and a full-flow drain off the bottom; run whichever faces your plumbing most directly. Use short flexible connectors at both fittings so the tank's thermal expansion never loads the threads.
Venting
Two 2-inch ports mean this tank can pass water fast, so vent it accordingly. A screened lid vent lets air follow the water in and out and keeps the narrow wall from dimpling under a quick draw.
Maintenance and Long-Term Care
Maintenance on the 175 is a quick quarterly habit — a look, a touch on the fittings, a glance at the vent.
Quarterly Inspection Checklist
- Visual: check the shell for distortion or a wet ring at a fitting.
- Fittings: hand-snug both 2-inch ports; a quarter turn past finger-tight, no wrench.
- Base: confirm the column stands flat and plumb on its pad.
- Vent: verify the lid vent is open.
Cleaning
As a potable tank, sanitize annually: drain, dose with unscented bleach at about a quarter cup per 15 gallons of clean water, hold two hours, and rinse until odor-free. The 8-inch lid is narrow, so a flexible brush or a low-pressure wand reaches the bottom of the deep shell best.
UV and Weather Protection
Black resin guards against sun, but if the tank lives fully exposed, look over the sunny face yearly and shade it where practical to stretch its life in a hot climate.
Alternatives and Comparisons
The 175 splits the difference between the slim 150 and the wider 250 — more water than the former, a smaller footprint than the latter. If you need the volume to move, a transport tank rides better; if you are feeding a basement system through a standard door, a doorway tank fits the opening. Stepping up, the 250-gallon water tank is the next stable size for a standing reserve.
Other 175-Gallon Options
Frequently Asked Questions
How long will the 175 Gallon Plastic Water Storage Tank last?
Within its 1.1 SG and 120 F limits and out of constant harsh sun, plan on 15 to 20 years. The seamless shell has nothing to fail at a joint, so a level base and reasonable shade are what carry it to the high end of that range.
What chemicals can I store in this tank?
It is a potable water tank, FDA-cleared for drinking water and food-grade liquids, and it handles light compatible solutions up to 1.1 specific gravity. Keep fuels, solvents, and flammables out, and store nothing heavier than 9.2 pounds per gallon. Check compatibility before storing anything new.
What kind of foundation does a 175-gallon tank need?
Full of water it weighs about 1,653 pounds — well under a ton — so a level gravel pad or a flat concrete floor carries it without engineered work. The point is flatness, not load capacity: the full 30-inch base should sit in even contact with nothing propping one side.
Does this tank come with a warranty?
Norwesco backs it for three years against any defect present from the factory — voids, pinholes, fittings. Overloading, incompatible chemistry, and impact damage fall outside coverage. Keep your receipt for any claim.
Can I install this tank underground?
No. This is an above-ground design; the walls cannot handle soil pressure. Choose an underground-rated tank for any buried installation.
Buying Considerations
Two checks before you order: a flat, firm spot the full 30-inch base can rest on, and contents that are water-weight or lighter (at or under 1.1 SG). For freight, this tank ships LTL on a pallet; residential delivery with a lift gate is available, so let us know if you lack a dock.
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