Muriatic acid
Pool pH down
Hydrochloric acid · 20° Baumé · ~31.45% HCl by weight · industrial-grade · used to drop pool pH and reduce total alkalinity
Product
Muriatic acid · 20° Baumé · ~31.45% HCl · "muriatic" is the trade name for industrial-grade HCl · the 20° Baumé / 31.45% strength is the standard pool / masonry concentration sold at hardware and pool stores
Use
Pool pH down · total alkalinity reducer · primary lever when trichlor isn't dropping pH fast enough · also rare uses: rinsing scale off ladders/tile, etching plaster
Dosing rule of thumb
Standard test-kit + dose calculator (e.g. Pool Calculator / TFP) — start with ¼ to ½ cup per 10,000 gallons to drop pH by 0.2; re-test after circulation. Never guess; always measure first.
Storage
Sealed jug · cool · ventilated · upright · away from chlorine products · HCl fumes will corrode nearby metal (rebar, equipment fasteners) over months · keep separated from all chlorinators
Location
pa · 6279 Greenhill Road, New Hope PA 18938 · pool equipment pad chemical storage
Safety. Concentrated muriatic acid causes severe burns and respiratory damage on contact. Always add acid to water, never water to acid — diluting in the wrong direction triggers an exothermic splash. Wear chemical gloves + eye protection + ventilation when handling. Never mix with bleach / chlorine / cal-hypo — releases chlorine gas. Store far from the chlorinator and from any open chlorine product.
Resources
- Doheny's Muriatic acid at Doheny's
- Hardware-store SKU Home Depot · muriatic acid · same chemistry, sometimes cheaper
- Dosing calculator TroubleFreePool dosing calculator — pick "pH" → "lower with acid" → enter pool volume + target
- SDS Muriatic acid SDS
Restock log
No entries yet. Track jugs purchased, supplier, paid price. Acid use is usually low — a single gallon often lasts a full season unless the pool runs very high alkalinity feed water.
Cross-references
- Pool category index — parent
- Doheny's 3-inch trichlor tablets — trichlor pushes pH down by itself, but muriatic is the heavy lever when test reads too high too fast
- Hayward chlorine feeder — the feeder is the chlorine side of the pH balance; this jug is the counterweight