Perlite Medium Only in a DWC?

Can I use only perlite for my medium in my DWC?

Answer: Yes, plain perlite can be used as (and makes an excellent) hydroponic growing medium. In fact, long tube shaped bags filled with straight perlite are often used commercially to grow many different crops. Simply place it into bags, or netted pots, or fill it into some other large container that you intend to flood and drain. Works well in drip systems, flood and drain systems, DWC systems....pretty much any hydroponic application perlite does well in. With DWC, just make sure you keep the nutrient solution well oxygenated by placing at least one air bubbler into the nutrient reservoir.

Keeping the temperature of the nutrient solution running through your system cool will also be important in keeping the nutrient solution oxygenated. Cool water holds more dissolved oxygen than warm water. Because plants can sometimes become temperamental when grown in standing water, it is important to keep the nutrient solution well oxygenated. It is, therefore, also very important to keep the nutrient solution temperature between 65 and 72 degrees, and NO HIGHER if at all possible. Once the first problems begin to occur due to warm nutrient solution temperatures or low oxygen levels, things tend to go down hill pretty quick after that. Hope this helps you out, and Happy Growing!