In order for your hydroponic system to thrive, you need to start with the right water. Water quality varies significantly from suburb-to-suburb and city-to-city. Tap water can contain various contaminants including chlorine, fluoride, minerals, and bacteria. Your system's water needs to have low total dissolved solids (TDS). TDS is the total amount of disolved minerals, salts, and metals in water. The TDS level is measured by parts per million (ppm). Starting with the right water makes it much easier to make adjustments after adding nutrients.
SA Water publishes complete analyses of the water supply system. They can be viewed here. In Adelaide, the TDS can reach up to 100 mg/L.
Water quality plays a crucial role in a hydroponic growing system. When you have created the right environment, provided the right nutrition, and optimized everything else in the grow room, the rest comes down to water.
By filtering your water, you can prevent contaminants from entering your hydroponic system. Starting with pure or 'dead' water also offers a clean slate from a nutrient standpoint. This allows for more precise and predictable nutrient dosing.
The main advantage of removing the existing salts from your hydroponics water supply is that nutrients are added at the grower’s discretion, making growing more predictable and calculable. The only nutrients that are present in the nutrient solution are the ones that are advantageous to the plant. Nutrients can also react with various contaminants in unfiltered tap water causing unpredictable results.
Filtered water also keep hydroponic systems cleaner for longer, requiring less maintenance and reducing the opportunities for diseases to thrive. High quality water leads to faster, healthier, and more robust plant growth.
The best way to remove contaminants and TDS from your water source is Reverse Osmosis or ‘RO’. Reverse osmosis filtration systems are very effective at reducing a wide range of contaminants, including salts and nitrates, bacteria, protozoa, viruses, arsenic, heavy metals, and minerals. We recommend the Reverse Osmosis Double Membrane Filter System.
Carbon/Sediment filters can also be effective in treating water for hydroponic systems. They are not as effective at filtering water as RO systems, but their advantage is that they do not impact water pressure. Always use water filters with high grade carbon matrix filters. We recommend products such as Hi Flow rather that household filters. The Hi Flow Water Filter System is a heavy duty sediment and carbon filter that does not impact water pressure. This is a much faster option than an RO filter.