300 Gallon Plastic Water Storage Tank - Black (46" x 50"): Complete Buyer's Guide
300 Gallon Plastic Water Storage Tank - Black (46" x 50") from Norwesco.
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 1.0 — the tank is engineered for liquids up to 1.0× the density of water (water is about 8.34 lb/gal). Confirm your fluid’s SG before storage.
Installation and Setup Guide
This is the stable way to keep 300 gallons of water: a 46-inch base under a 50-inch body makes a tank that is nearly as wide as it is tall, so the loaded weight settles low and broad and the worry about tipping all but disappears. A flat, firm pad still does the real work, but the generous footprint forgives far more than a tall column would.
Site Preparation
Build a level four-inch concrete pad or a compacted crushed-stone bed a few inches past the 46-inch base in every direction. Hold it flat across the full width so the tank loads its floor evenly; a wide tank on a sloped base still drives extra stress to the downhill edge. Loose gravel and bare soil rut under repeated filling and draining, so avoid them.
Placement and Connections
Plumb the discharge from the lowest fitting and keep the line short to minimize friction and leak points. Tie the first section in with a flexible coupling instead of rigid pipe — a black shell warms in the sun and moves as it fills, and a stiff line carries that into the bulkhead until it weeps. Snug the threads by hand and stop a quarter turn later; never a wrench.
Venting
Match air to water: keep the lid vent open and screened so the tank pulls air in on draw-down and pushes it out on fill. A wide tank tolerates a vent hiccup a little better than a slim one, but a fully blocked vent will still dimple the top under a hard pump-out, so keep the screen clear of nests and grit.
Maintenance and Long-Term Care
Looking after 300 gallons of drinking water in this squat black tank is quick, and the dark wall keeps algae starved of light. The short routine below is about freshness and an occasional structural glance — a wide, low tank is inherently stable, so most of your attention goes to water quality.
Quarterly Inspection Checklist
- Wall sweep: Circle the 50-inch body and check the lower wall for any outward swell that would point to a settled pad or overweight contents.
- Fitting tug: Hand-tighten the outlet if it has crept; poly relaxes around threads and a wrench only damages it.
- Pad audit: Confirm the wide base is fully supported and that no edge has been undercut by erosion.
- Vent check: Verify the screened lid vent is clear so air moves freely in both directions.
Cleaning
Empty the 300 gallons through the bottom outlet once a year, rinse the interior, then sanitize on the refill with about a quarter cup of unscented bleach per fifteen gallons, holding two hours before flushing the chlorine away. The annual reset clears the sediment that settles across the broad floor and keeps the reserve fresh.
UV and Weather Protection
Black gives this tank the strongest UV resistance of any color it is offered in, but the resin's stabilizer still erodes over years outdoors. Check the sun-facing side annually for chalk; the low, wide form is also simple to shade if it sits in punishing light.
Alternatives and Comparisons
This 46-by-50 black tank is the stable, low-profile take on 300 gallons, where the taller version wins on floor space instead. Step down to ease the pad and the freight, or step up where you need a deeper reserve. The choices below help you weigh stance against footprint.
Other -Gallon Options
Frequently Asked Questions
How long will the 300 Gallon Plastic Water Storage Tank - Black (46" x 50") last?
With a level pad, sane fills, and the light annual sanitize, this squat 300-gallon black tank runs well past fifteen years. Its seamless wall has nothing to delaminate and black is the toughest UV color available; the low, wide stance also makes a tipping failure essentially a non-issue. Stale water, not the resin, is the usual life-limiter.
What chemicals can I store in this tank?
It is built and FDA-approved for potable water and food-grade liquids and will hold the lighter farm solutions within reason. Keep fuels, solvents, and flammables out, and verify any chemical against a poly compatibility chart first, since a few oxidizers attack polyethylene even though most acids and bases do not.
Does this tank come with a warranty?
Yes. Norwesco's warranty covers defects in materials and workmanship under normal use — factory faults only, not overfilling, a poor install, chemical damage, or impact. Keep your receipt and an install photo to make any claim simple.
Can I install this tank underground?
No, it is above-ground only. The flat wall cannot resist soil pressure, so burying it would collapse the tank and void the warranty. Use a ribbed, reinforced underground cistern for below-grade water storage.
Buying Considerations
Confirm the wider footprint fits your spot with room to work, that the pad can be brought level even though this tank is forgiving, and that you have a firm place ready for offload — at 300 gallons it ships easily but still wants a flat landing.
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Questions? Call (866) 418-1777 — our team knows these products inside and out and can help you select the right tank for your application.
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