Chlorine, Bromine, Salt, or Peroxide?

Not all sanitizing systems are created equal — and not every option works for every type of stock tank. Chlorine, bromine, hydrogen peroxide, and salt all keep your water clean, but each has different costs, maintenance needs, and effects on galvanized vs. poly tanks. Here’s what to know before you choose.

1. Chlorine

• How it works: Most common pool sanitizer. Kills bacteria, viruses, and algae quickly. Comes in liquid, tablets, or granules.

• Best for: People who want low-cost, widely available sanitation with easy test strips.

• Impact on tanks:

  • Poly: Safe, no issue.

  • Galvanized: Can be harsh on the metal. Over time, chlorine speeds up rusting/corrosion, especially at higher concentrations or if water balance (pH/alkalinity) isn’t maintained.

2. Bromine

• How it works: Similar to chlorine but works better in warmer water and holds up longer in the sun. Often used in spas/hot tubs.

• Best for: People who want a softer feel, less odor, and more stable sanitation in heated tanks or sunny setups.

• Impact on tanks:

  • Poly: Safe, no problems.

  • Galvanized: Still corrosive over time, though slightly less aggressive than chlorine. You’ll still risk rusting unless you maintain water balance carefully.

3. Hydrogen Peroxide (Biguanide-style systems)

• How it works: Non-chlorine option. Works as an oxidizer that kills bacteria/algae, but less powerful than chlorine/bromine. Requires frequent testing and higher doses.

• Best for: People with sensitive skin, chlorine allergies, or those wanting a more “natural” feel. Also, good if you want to avoid the chlorine smell.

• Impact on tanks:

  • Poly: Safe, no issues.

  • Galvanized: Much gentler on metal than chlorine/bromine, so tanks last longer. However, it’s more maintenance-heavy and expensive in the long run.

4. Salt System

• How it works: Uses salt + generator to convert salt into chlorine. So it’s still chlorine, but at a softer, lower dose.

• Best for: People who want a “set it and forget it” system with less chemical handling and a more natural, silky water feel.

• Impact on tanks:

  • Poly: Perfect — salt systems are ideal here because plastic isn’t affected by corrosion.

  • Galvanized: Not recommended — salt accelerates rust and will eat through metal fast.

Quick Guide: Who Should Choose What?

• Budget-conscious / easy upkeep → Chlorine (but avoid in galvanized if you want long tank life).

• Hot tubs or heated tanks → Bromine (stable at higher temps, softer feel).

• Sensitive skin / chemical-free preference → Hydrogen Peroxide (but requires diligence and costs more).

• “Set it and forget it” / silky water feel → Salt system (only for poly tanks, never galvanized).