Hydroponic Reservoirs & Nutrient Storage Tanks
The hydroponic reservoir is the operational hub of any recirculating growing system. It holds and circulates the nutrient solution that feeds your plants, houses your water pump and aeration equipment, and provides the volume buffer that stabilizes pH and EC between feeding cycles. Reservoir sizing and management directly affect the stability of your entire hydroponic operation.
Choosing the Right Reservoir Size
The general rule in hydroponic reservoir sizing is to go larger than you think you need. Larger water volumes buffer nutrient and pH fluctuations more effectively — a small reservoir experiences dramatic pH and EC swings as plants feed, while a large reservoir changes slowly and gives you time to correct before plants are affected. For DWC systems, a minimum of 5 gallons per plant is a common starting point; RDWC central reservoirs for multi-bucket systems typically run 20–100 gallons or more. For flood and drain systems, size the reservoir to hold enough solution to completely flood the grow tray with volume to spare. For drip systems, size to store at least one full day’s irrigation volume to prevent running dry between refills.
Reservoir Aeration, Temperature & Maintenance
Plants require dissolved oxygen in the nutrient solution, and reservoirs need continuous aeration to maintain it. Connect an air pump and air stone or diffuser to the reservoir to saturate the solution with dissolved oxygen — this also prevents stagnant water conditions that favor root pathogens. Keep reservoir temperature between 65–75°F — warmer water holds less dissolved oxygen and promotes bacterial growth; cooler water slows plant metabolism. Use a water chiller in warm climates or during summer operation to maintain the optimal temperature range. Change the full reservoir solution at least every 14 days during vegetative growth and weekly during flowering to prevent nutrient imbalance and pathogen accumulation. Test pH and EC daily with a pH meter and EC meter, adjusting as needed to maintain your target ranges.
Reservoir Accessories & Automation
Reservoir lids and covers prevent contamination, reduce evaporation, and block light to prevent algae growth. Float valves automate top-off as water evaporates between full changes. For commercial operations, automated pH and nutrient dosing systems eliminate manual monitoring entirely. Use our Nutrient Mixing & Dilution Calculator to plan concentrated stock solutions for your reservoir volume and target EC.
Pair your reservoir with a complete hydroponic system, browse water pumps for circulation, or explore our full Hydroponics 101 guide in the Learning Center. Fast shipping.
