Nutrient solutions require regular management. There are meters to measure the strength (conductivity) and pH of the solution and there are solutions to make adjustment. It is all pretty straightforward once you have the hang of it, but it is a big part of getting things right.

Nutrient Management - more information (MS-Word document).

	Bluelab Combo Meter A conductivity, pH and temperature meter all in one.
	Bluelab EC Truncheon A completely original approach to Electrical Conductivity measurement.
	Bluelab pH Meter A rugged, reliable and affordable pH meter.
	Bluelab Soil pH Meter A rugged, reliable and affordable soil pH meter.
	EC Standard 1.413 mS A standard solution set at 1.413 mS
	EC Standard 2.76 mS A standard solution set at 2.76 mS
	Hanna Champ Hanna's budget model pH meter.
	Hanna EC Meter - Dist 4 A benchmark Electrical Conductivity meter.
	Hanna pHep Meter Hanna's premier pH meter.
	Hanna pHep Meter - Waterproof This is the waterproof version of the famous pHep pH meter.
	pH Buffer 10 A buffer solution set at pH 10.
	pH Buffer 4 A buffer solution set at pH 4.
	pH Buffer 7 A buffer solution set at pH 7.
	pH DOWN An acidic solution, used to adjust the pH of nutrient solutions downward.
	ph PRO Digital pH Meter A best selling and extremely high quality pH meter.
	pH Test Kit A simple and inexpensive way of measuring pH.
	pH UP An alkaline solution, used to adjust the pH of nutrient solutions upward.