Hydroponic Tanks and Reservoirs

What reservoir set up is best for you?

It doesn’t matter what kind of hydroponic setup you are using you will always require storage for your nutrient solutions. Hydroponics is entirely based on growing your plant with water rich in nutrients which are necessary for all stages of life from seedling to harvest so what to buy, where to place it and utilize it is good to get right from the beginning.

Before you read this maybe it is best to check out our grow room planning section and hydroponics systems setup section.

Floating or Water Culture (basic no pump)

This type of reservoir allows the plants to float above the nutrient solution and dangle their roots in which allows them to suck up all the nutes required. A typical example of this is watching a potato suspended in a glass jar with its roots in the water below but it can be used in basic indoor growing.

Wick (basic no pump)

Again, this is a basic system with the reservoir situated directly under the plants. The plants are situated in a more soil like growing medium and large thick ‘wicks’ like cotton rope are placed in the nute solution and are funnelled up into the growing medium. Capillary action will cause the nutrients to flow upwards keeping the growing medium moist at all times.

Drip or Top Feed (pump)

Whereby the reservoir is usually situated underneath the plants, pumping the solution above the plants which then drip feeds them using emitters. The excess nutrient solution then makes its way through the plant pots and back into the reservoir via the drainage holes.

Ebb and Flow (pump)

One of the most common and more professional methods whereby the pot plants sit right on a tray that the reservoir fills. The tray is open, set up off the ground and is flooded up to around 6 inches around four times per day from the reservoir. Once the tray has been flooded the solution then drains back to the reservoir, you should have an overflow pipe system installed just in case of excess pumping. The reservoir is again situated below the plants.

Nutrient Film technique (NFT)

This system is very similar to the Ebb and Flow method with your plants sitting in a tray and that tray being fed a nutrient solution from the reservoir. However the solution is constantly pumped through the tray with a thin ‘film’ of it accessible by the plants at all times. The reservoir can be situated anywhere as long as the pump can do its work and the excess solution is able to drain back into it. So you can have larger barrels of solutions with this and the Ebb and Flow methods.

Reservoir size

Small hydro setups and large commercial setups pump the nutrient solution around to your plants on a regular basis. You will lose quite a lot of your solution through the growth of your plants and evaporation so try to buy a vessel that can supply at least one week if not two weeks worth of plant food. Having a lid will help reduce evaporation. So think bigger than smaller and depending on your growing setup you may be able to use stand up barrels.

Reservoir location

Try and think about your hydroponic setup and placement of the reservoir prior to buying it. Remember that all the water you need to add on a regular basis will need to be transported to the vessel and poured in so close to a water supply or having the ability to get a hose to the area is ideal. Drainage of the solution and cleaning is also an issue and it is sometimes why people like to use old bathrooms and the bath itself as the reservoir.

Extra reservoir and temperature

Why would you need a second or third vessel? Well the main reason would be to keep water in it ready for use. Water that has been left to stand overnight will release chlorine and other chemicals and hopefully be closer to pH neutral than water straight out of the faucet. It also means the plants will receive water at room temperature which will elevate any shock that water from the outside might have caused. On that note, even though your plants may be bathing in the heat produced from your lights in their little eco system above the reservoir or inside a grow tent their roots might not be so warm. If you are growing in a large room, one with drafts or in a colder climate you may find that the temperature of your nutrient solution sitting on the floor could get quite cold and plants don’t like that, they like the tropics! Some easy solutions are to raise the vessel off the floor on to bricks, wrap the outside in foam or other insulation and maybe include an aquarium heater in the water to keep it at a steady warm temperature. Look to attain a temperature of between 18°C = 65°F and 24°C = 75°F

Cleaning

Best practice is to empty and clean the reservoir each week to keep pests and mold out of the system. However, if you run a tight ship and your environment is generally very clean, away from the outdoors and your vessels have tight lids and connections then you might need to do very little cleaning. You may also want to invest in bacterial and pathogenic protected tubing and fittings.