When Cleaning Goes Wrong: The Perils of Using Hydrochloric Acid on Filter Cartridges

The photo above shows a set of wire-wound filter cartridges that have literally half disintegrated after being cleaned with hydrochloric acid (HCl). At first glance, acid seems like a logical choice for cleaning — after all, it dissolves scale, rust, and mineral deposits very effectively. But in water treatment and bore maintenance, the choice of cleaning agent can be the difference between extending the life of your equipment and destroying it.

Why Hydrochloric Acid is a Problem

Hydrochloric acid is a strong, highly reactive mineral acid. While it can rapidly dissolve calcium carbonate and iron oxides, it also aggressively attacks the organic fibres and adhesives that hold filter cartridges together. In this case, the polypropylene and cotton windings have been stripped away, leaving only a skeleton of wire. The result? A cartridge that is no longer capable of filtering water effectively and needs immediate replacement.

The False Economy of Harsh Cleaning

Often, acid cleaning is attempted to “save money” by reusing cartridges instead of replacing them. In reality, the opposite happens:

• Shortened Cartridge Life – instead of lasting for multiple cycles, the filters fail after a single acid wash.

• System Downtime – damaged filters allow particulates to bypass, risking downstream equipment or contaminating storage tanks.

• Hidden Costs – corrosive fumes and residual acid can also attack housings, seals, and stainless-steel components.

Safer Alternatives

If you’re dealing with iron fouling, manganese deposits, or calcium build-up, there are better approaches than hydrochloric acid:

• Specialist Cleaning Solutions – biodegradable, bore-safe cleaners such as BoreSaver formulations are designed to dissolve mineral and biological fouling without damaging system components.

• Proper Cartridge Maintenance – some cartridges are designed for single use and should be replaced rather than cleaned. Where washable options are needed, select cartridges specifically rated as “reusable.”

• Preventative Treatment – addressing the chemistry at the source (e.g., pH adjustment, iron removal systems, or pre-treatment) reduces the burden on downstream filters.

Key Takeaway

The image tells the story: what looked like a “cost-saving clean” actually destroyed the cartridges and added to replacement costs. In water treatment, the cleaning chemical needs to be matched not only to the fouling type but also to the materials of construction. Hydrochloric acid has its place — but filter cartridges are not it.