Hydroponics: Need a Good Flush? Flushing Agents can Help!

How to use flushing agents in your hydroponic system

Speaking of clean, how clean is your hydroponic system these days? A healthy harvest requires a clean growing area. If you’re growing hydroponically, then keeping your system clean and your nutrients balanced is also crucial to success. Salt buildup, algae, and other debris can inhibit plant growth impact the quality of your harvest.

Plants grown hydroponically using mineral nutrients can often experience nutrient imbalances; excess minerals and additives can build up inside plant tissue. The result can be plant damage and poor flavor in your harvest. When you get close to harvest time, do your plants seem to get a little peaked? Flushing can help. You might have also over-fertilized and need to correct the problem. Flushing your system can help plants get the nutrients they need and remove buildup of unwanted chemicals in the plant.

The easiest way to flush your system is to simply supply your plants straight water with no nutrients added for the last week to two weeks before you harvest them. This will force the plants to use up any of the excess stored nutrients or additives they’ve retained in their tissue. However, using just water may not thoroughly clean your system or the plants. Flushing agents can aid you in both cleaning your system thoroughly and better correcting nutrient imbalances.

Example product: Grotek Final Flush eliminates excess fertilizer salts in the final stages of growth and can also be used to correct overfeeding or for desalinization of reusable growing media.

How to clean and flush your hydroponic system with a flushing agent in 5 easy steps:

1. Depending on your type of hydroponic system, you’ll need to drain the reservoir. Recycle the old water by using it in your landscape or container plants. The residual nutrients in the reservoir water can give your outdoor plants a boost.

2. Clean the reservoir completely. Remove all sediment, algae and other pollutants that might be present. It might be necessary to scrape the algae off the sides. If you have a lot of algae build up, you’ll probably want to use an algae cleaner. Using a cleaning product such as Safer Moss & Algae Cleaner & Killer will make this task a breeze. Then, be sure to rinse the reservoir thoroughly.

3. Now refill your reservoir with water and your choice of flushing agent and pump it through the system. A flushing agent makes the cleaning process quicker and more efficient. Be sure to follow the directions on the flushing agent label so you don’t use more than you need to.

Example product: General Hydroponics FloraKleen removes fertilizer residue that can accumulate over time in hydroponic systems, growing media, and potting soils.

4. Once you’ve flushed the system, discard the water and refill the system with plain water. Test the pH of your water and adjust appropriately. Run your system for 24 hours.

5. Drain your system once more and refill the reservoir with fresh water and nutrients. Or, if this is a final flush before harvest, you may refill using water only. (Learn more about how to manage the nutrient solution in your system).

Example product: X Nutrients Flushing Solution is designed to flush away fertilizer salts and residues that accumulate in a plant’s stems, leaves, flowers and buds. Your crops will be healthier and cleaner.

Some growers will do a short flush every two weeks, while other will only flush their system once during a plant’s growing cycle; about one to two weeks prior to final harvest. Techniques will vary depending on your water quality, the type of plants you’re growing and the length of their growing cycle.

Did you know you can use flushing agents in soil and coir growing mediums too? Again, if you’re using mineral nutrients (synthetic fertilizers) in your potted crops growing in a soil or coir-based medium, excess nutrients can still build up in your plants. You should flush your container plants before harvest as well.