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Aluminum Chlorohydrate Storage — ACH Coagulant Tank Selection

Storing Aluminum Chlorohydrate (ACH)? Start Here

ACH is a water-treatment coagulant — a mildly acidic aluminum solution that's gentler than alum and a clean fit for a poly tank. It's the standard coagulant for low-alkalinity source water because it doesn't crash the pH the way alum can.

Can you store it in a poly tank? Yes — the standard.

ACH (pH ~3.8–4.5, with chloride) stores in HDPE rotomolded tanks with PVC/CPVC piping, EPDM gaskets, and PP fittings — 1,500–15,000-gallon bulk tanks are typical at municipal water plants. Keep metal off wetted parts (the chloride pits stainless). For drinking water, use NSF-60 product and an NSF-61 tank.

The safety that actually matters

  • Mildly acidic — standard acid PPE, vented tank, 110% containment.
  • Non-metallic wetted parts (PVC/CPVC/poly) to avoid chloride corrosion.

Common questions

Poly OK for ACH?
Yes — HDPE with PVC/CPVC piping and EPDM gaskets is the municipal standard.
ACH or alum?
ACH consumes less alkalinity per dose, so it's preferred for low-alkalinity water where alum would crash the pH.

Aluminum Chlorohydrate storage tanks from OneSource

For aluminum chlorohydrate storage, specify HDLPE_OR_XLPE rated to specific gravity 1.9. Verified, compatibility-matched options:

Confirm chemical compatibility and a ZIP freight quote with our team at 866-418-1777.

Designing the storage system, not just picking a tank?

Vendor-neutral engineering guides from our custom fabrication team - material of construction, containment, and code, matched to your chemistry.

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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.

  1. PubChem Compound Database — entry for Aluminum Chlorohydrate (CID 71586946, CAS 12359-72-7). pubchem.ncbi.nlm.nih.gov. National Library of Medicine / NCBI. Canonical chemical-identity reference.
  2. 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.
  3. 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.
  4. 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).
  5. 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.
  6. 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.
  7. NIOSH Pocket Guide to Chemical Hazards — occupational exposure limits, PPE, and IDLH data for Aluminum Chlorohydrate. cdc.gov/niosh/npg. CDC / NIOSH chemical-specific occupational-safety reference.