Tuesdays tips for beginner growers are brought to you by HIGH TIMES Cultivation Editor Nico Escondido. 1. If you are growing in Rockwool be sure to measure the PPM levels of your run-off after watering. PPM levels over 1000 indicate a build up of salts and you should flush plants with pure water (only) for the next week. 2. The dark cycle is very importanteven for plants in a veg state. At night leaves transfer energy down to the root zone which is when the roots are breathing in oxygen and growing. 3. As light density increases CO2 levels should increase proportionately. CO2 levels of up to 2500 PPM can be used in gardens with high-intensity discharge (HID) lighting. CO2 generators are by far the most effective in generating these PPM levels. Follow Nico on Social Media: @Nico_Escondido (Twitter) amp; @Nico_High_Times (Instagram) Dont Miss Last Weeks Tips! Keep up with all of HIGH TIMES grow coverage HERE. by Nico Escondido at High Times