Aluminum Sulfate (Alum) Storage — Tank System Selection
Storing Alum (Aluminum Sulfate)? Start Here
Alum is the classic coagulant for drinking-water and wastewater clarification. It stores easily in a poly tank — the one firm rule is no metal on the wetted parts. Even stainless pits in alum over time, so the fittings stay non-metallic.
Can you store it in a poly tank? Yes.
Liquid alum is compatible with HDPE and XLPE tanks (an ASTM 1.5 SG rating is enough for the solution). Use PVC fittings and EPDM gaskets. Viton isn't needed here — EPDM is correct. The important part: avoid mild steel, galvanized, aluminum, and even stainless on wetted parts — alum pits them. Keep it all PVC/poly.
The safety that actually matters
- Non-metallic wetted parts only — PVC fittings, EPDM gaskets.
- Mildly acidic — standard eye protection and 110% containment.
- For drinking water, use NSF-60 product and an NSF-61 tank.
Common questions
- Can I use stainless fittings on an alum tank?
- No — even stainless pits in alum over time. Use PVC fittings and EPDM gaskets, no metal on wetted surfaces.
- What SG tank do I need?
- A 1.5 SG chemical-service tank covers liquid alum; 1.9 gives extra margin.
- Is poly fine for a coagulant feed tank?
- Yes — it's the standard. Size the day tank for your dose and pair with a compatible metering pump.
Aluminum Sulfate (Alum) storage tanks from OneSource
For aluminum sulfate (alum) storage, specify HDLPE_OR_XLPE rated to specific gravity 1.5. Verified, compatibility-matched options:
- Snyder Industries 22 Gallon ASTM XLPE Black Heavy Duty Vertical Storage Tank (1.9 SG)
- Snyder Industries 150 Gallon XLPE Chemical Feed Station Tank (1.9 SG)
- Snyder Industries 500 Gallon ASTM XLPE Black Double Wall Tank (1.9 SG)
- Snyder Industries 1500 Gallon 45 Degree XLPE Cone Bottom Tank in White (1.9 SG)
- Snyder Industries 5000 Gallon XLPE Vertical Liquid Storage Tank with ASTM Certification (1.9 SG)
Confirm chemical compatibility and a ZIP freight quote with our team at 866-418-1777.
Sources & References
All compatibility ratings, hazard classifications, and chemical identifiers on this page are sourced from authoritative third-party publications. Verify against the original references before final specification.
- PubChem Compound Database — entry for Aluminum Sulfate (CID 24850, CAS 10043-01-3). pubchem.ncbi.nlm.nih.gov. National Library of Medicine / NCBI. Canonical chemical-identity reference.
- Snyder Industries Chemical Resistance Recommendations — system-of-construction guidance for polyethylene chemical-storage tanks at industrial ASTM 1.9 SG design rating. SNY-3041 Chemical Resistance Chart. Snyder Industries, current edition. Resin + fitting + gasket + bolt MOC matrix.
- Equistar Technical Tip — Chemical Resistance of Polyethylene — LDPE / MDPE / HDPE rating chart by concentration and temperature, distributed by Enduraplas. enduraplas.com (PDF). Equistar polyethylene resin chemical-resistance data, distributed via Enduraplas.
- NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response. nfpa.org. NFPA 704 'fire diamond' health/flammability/instability/special-hazard rating system (0–4 scale).
- UN Globally Harmonized System of Classification and Labelling of Chemicals (GHS), current revision. unece.org/transport/ghs. GHS pictograms, signal words, and H-statement codes referenced in this guide.
- ASTM D1998 — Standard Specification for Polyethylene Upright Storage Tanks, current edition. astm.org. Cited as the design-specific-gravity standard (typically 1.9 SG) for industrial chemical-service polyethylene tanks.
- NIOSH Pocket Guide to Chemical Hazards — occupational exposure limits, PPE, and IDLH data for Aluminum Sulfate. cdc.gov/niosh/npg. CDC / NIOSH chemical-specific occupational-safety reference.