5 Tips to Nourish Your Recirculating Hydroponic System

Most hydroponic growers utilise run-to-waste setups, in which the nutrient solution is distributed to the plants and then thrown away. However, to minimise waste, the industry is now moving towards recirculating hydroponic systems, which reduce water usage and fertiliser dumping into sewage systems. This setup, known to be much friendlier to the environment, is praised for its overall advantages.

While it may seem to be a good solution, some growers have shown concern over successfully sustaining plants in this new system. A recirculating setup offers many benefits while providing even better yields than run-to-waste arrangements. As long as the grower appropriately manages the nutrient solution and swaps it during the growing cycle, the recirculating setup will be successful. 

Here are five tips to nourishing a recirculating hydroponic system sufficiently:

Ensure Adequate Reservoir Volume

A hydroponic system reservoir must have at least ten times the necessary volume for one irrigation. This volume is essential because the bulk of the solution must stay unaffected during the nutritional changes caused by plants. Most of the solution should be inside the tanks, not inside the media with each irrigation done.

A quick way to remember this is to ensure that the volume of your initial reservoir is at least ten times that of what is necessary to execute one irrigation of your entire crop. Doing this will allow the water and nutrient absorption effects to occur slowly. 

Circulate Solution Until pH and Electrical Conductivity Are Constant

Once an irrigation cycle starts, the solution combines with the last irrigation cycle’s remnants. This new mixture will make the return’s pH and EC different from the main tank. Ensure that you implement the recirculating process until the tank’s EC and PH remain constant while matching the return pH and EC. This process will ensure that your plant’s root system is exposed to the intended nutrient concentrations. 

When this is complete, you know that the media has equalised with the solution’s bulk. At this point, you can stop the irrigation process, but continue to monitor pH and EC levels within the tank. 

Add Water When EC Increases

With each subsequent irrigation, add water instead of nutrients when EC increases. In a regular recirculating system, the main tank’s EC solution usually increases with each irrigation, while the solution’s total volume decreases. When this occurs, it’s a sign your plants are healthy, as well-functioning plants always take in more water than nutrients. You’ll want to pour enough water to lower EC to desired levels, but make sure you don’t add nutrients to avoid increasing EC or cause an imbalance of nutrient levels in the solution.

When you do this, ensure that the tank’s pH is corrected with each irrigation and water addition. Correct nutrients levels are optimal for the plant’s growth and to maintain steady levels in your system.

Replenish Water With Nutrients When Volume Is Down

When your tank’s volume is down to 40 per cent, it’s time to shift the solution. As time goes by, your solution’s volume will go down even when you add more water to elevate the EC. Once the volume hits 40 per cent, you must fill the tank to its full volume along with water and nutrients.

If you’ve wanted to change nutrient ratios, this is the perfect opportunity to do so. However, this process cannot be implemented indefinitely, as this may result in nutrient imbalances. To avoid this, fully change the solution every three to four weeks. 

Use In-Line UV and Carbon Filters

Keeping your hydroponic system free of contaminants is essential to its health. Your plants must have uninterrupted access to its nutrient solution, and microorganisms can halt its growth. To keep your plants free of microorganisms, use in-line UV filters and carbon filters. UV filters will ensure that the nutrient solution stays as sterile as possible, and carbon filters remove plant exudates that may contaminate the nutrient solution.

Plant exudates are food for microorganisms, making them a prime place for microorganisms to gather. Other exudates are plant hormones that may cause undesired responses. Fortunately, these issues are easy to avoid by using filters. However, it would be best if you remembered to use UV-resistant chelates with less affinity for carbon filters, as these filters may destroy heavy metal chelates.


A recirculating hydroponic system is a wonderful way to grow plants. It produces much less waste, making it safe for the environment. It also produces better yields, which makes it a setup that pays for itself! Providing adequate amounts of nutrition can be a challenge, but by following these five tips, you’ll enjoy the successes of your system in no time.

Looking for natural plant growth enhancers? Let us know at Moonshine Global! Our product, the Moonshine Nutrient Enhancer, is a brewed plant bio stimulate designed to promote exceptional plant growth, health, and terpene production. It is 100% biodegradable and contains no carcinogens or PGRs. Get yours from our online shop today!