Algae in Hydro and Aeroponics

Light plus warm, nutrient-rich water grows algae. Opaque, light-tight hardware is the main fix.

pests hydro light watering

Full book

Where it grows

Example strains

warmth light and nutrients

Example strains

clear tubes reservoirs buckets exposed rockwool and leaky DWC lids

Aromaattached algae can look velvety or slimy on walls and roots

Aromaswimming types still clog lines and sprayers

a film on roots starves them of air

algae compete for the same nutrients

in the dark they consume dissolved oxygen and release CO2

slime clogs tubing, pumps, and aeroponic jets

black, not clear or translucent

opaque tank and a light-tight lid

opaque containers only

cover rockwool with landscape fabric, white-black plastic (white up), or purpose-made lids

empty, scrub, and replace or wrap anything that still leaks light

a 0.5 to 1 percent hydrogen peroxide solution is listed; it also kills mycorrhizae and other microbes

the same germicidal approach used on tanks and hot tubs

low-ppm colloidal silver, grapefruit seed extract, and barley-straw rafts with limited effect

Paraphrased from Ed Rosenthal's Marijuana Grower's Handbook. Educational grow reference, not medical advice. Follow local law.

Credit: Ed Rosenthal, Marijuana Grower's Handbook

Leafy may reference this article when answering related grow questions.