Essential knowledge for all hydroponic systems - keep your plants healthy with proper reservoir care
๐ pH Management
Target Range: 5.5-6.2 for hydro/coco, 6.0-6.8 for soil-based
Why it matters: Wrong pH locks out nutrients even if they're present. Check daily in small reservoirs, every 2-3 days in large systems.
Tools: Bluelab pH pen (most accurate), GH pH Control Kit (budget), pH Up/Down solutions
โก EC / PPM Monitoring
EC = Electrical Conductivity: Measures total dissolved salts (nutrient concentration)
PPM = Parts Per Million: Another way to express nutrient strength (EC x 500 or 700 depending on scale)
Targets: Seedlings 0.4-0.8 EC | Veg 1.2-1.8 EC | Bloom 1.8-2.4 EC
Tools: Bluelab combo pen, Milwaukee EC meter
๐ก๏ธ Water Temperature
Ideal Range: 65-72ยฐF (18-22ยฐC)
Why it matters: Above 72ยฐF = low dissolved oxygen + root rot risk. Below 60ยฐF = slow growth.
Solutions: Water chiller (best), frozen water bottles (budget), beneficial bacteria (Hydroguard) if temps unavoidable
๐ฆ Beneficial Microbes vs Sterile
Beneficial Route: Add Hydroguard, SouthernAg GFF, or Recharge. Protects roots, prevents pathogens. Requires warmer temps OK (up to 75ยฐF).
Sterile Route: Add H2O2 (hydrogen peroxide) or pool shock (sodium hypochlorite). Kills everything. Requires perfect temps (65-68ยฐF).
Pick one - never mix both!
๐ Change Frequency
Small systems (DWC, 5-gal buckets): Weekly full change recommended
Medium systems (20-50 gal): Every 10-14 days
Large systems (100+ gal): Every 2-3 weeks, top-off between changes
Drain-to-waste: No changes needed - fresh nutrients every watering
๐งช Mixing Order
ALWAYS FOLLOW THIS ORDER:
- Fill reservoir with water (RO or dechlorinated tap)
- Add silica first (if using) - wait 10 min
- Add nutrients (Part A, then B if 2-part)
- Add CalMag (if using)
- Add supplements (bloom boosters, enzymes, etc)
- Mix thoroughly, wait 15 min, then pH adjust
- Never add concentrated nutrients together (precipitates form)