Mix feed accurately, understand pH and EC, and keep the root zone stable without chasing every number.
Use a complete feed labelled for hydroponics and your water type or crop stage. Follow its label by volume, add parts separately to the reservoir and measure the result instead of copying an internet recipe.
pH affects nutrient availability; EC estimates the total concentration of dissolved ions. EC cannot tell you which nutrient is missing, so use both measurements as trends alongside plant and root observations.
Fill with water first, measure each concentrate accurately, mix between additions and make pH adjustments last. The product label—not a generic chart—sets the starting dose.
Hard water can push pH upwards and contributes minerals before feed is added. A hard-water nutrient formula and consistent measurement solve many domestic cases; treatment is not automatically necessary.
Rainwater is low in dissolved minerals but its quality depends on the roof, gutters, storage and local contamination. Filter it, inspect it and avoid treating “natural” as a guarantee of cleanliness.
Top up water between planned solution changes, but reset the reservoir periodically because plants do not take every ion in equal proportions. Let readings, crop stage and cleanliness guide the interval.
Warm nutrient solution holds less oxygen and can favour root problems; very cold solution slows plants. Prevent direct sun on reservoirs and manage room heat before buying a chiller.