Hydroponic Systems

First System Run (Priming): Flushing, Disinfection, and Verification

2 min read March 8, 2026

Step 1: Flushing

Fill with clean water, circulate for 30–60 minutes, then drain. Repeat twice. EC after flushing should be ≤0.3 mS/cm — if not, continue flushing.

Step 2: Disinfection

DisinfectantNotes
Hydrogen peroxide 3–5%Safe, breaks down to water within 30–60 minutes
Sodium hypochloriteEffective, requires thorough rinsing afterwards
QAC compoundsEffective against biofilm; must be fully removed before planting

After the contact period — a minimum of 2 clean-water flushes.

Step 3: Test Run (24 Hours)

Check:

  • Pump flow stability
  • Timers triggering on schedule
  • pH and EC stability after 12 hours
  • No leaks anywhere in the system

Three Mistakes That Cost the Most

  1. Skipping the flush — new plastic contains lubricants and plasticisers
  2. Not maintaining the disinfectant contact time
  3. Planting immediately after disinfection without a test run

Ready-to-Plant Criteria

  • EC and pH stable for 12 hours
  • Pump and timers functioning without fault through two full cycles
  • No leaks detected
  • Drain EC equals input water EC