How to Maintain a Hydroponic Nutrient Reservoir

A solid foundation for maintaining your hydroponic nutrient solution reservoir! A reservoir forms the center of every single type of hydroponic growing system. These basics give you effective control over every system type. Be a successful hydroponic gardener by effectively maintaining your nutrient solution reservoir.

1. These notes are for a wide range of vegetables used for human consumption. For growing illicit drugs look elsewhere.
2. A wide range of vegetable types need a wide range of nutrient and pH levels. Guides are available from the internet and some nutrient suppliers
3. Check the water quality with your TDS/PPM EC meter from a sample before putting it in your reservoir. Tap water measuring 300 ppm or greater indicates that you may need to run either a reverse osmosis system or distill your water. You want to be sure of the total PPM of the water you are putting to your plants, BEFORE adding nutrients, is between 0-50ppm, anything over 100 is acceptable just be wary of some of the micro nutrients that might be in your test water. See the "Tips" section for ideas on tap water usage.
4. Use a digital probe to measure the strength and pH of the nutrient solution every day and do this close to the same time every day. Make notes in a diary to keep track of events and changes.
5. With nutrients in your reservoir, you can't get a proper reading with paper strips or test tube drop kits. For more accurate readings of your test equipment, test after the nutrient has been run through your system at least once (twice is good).
6. Adjust the pH of your nutrient solution using propriety solutions such as pH Up or pH Down accordingly. Note: An adjustment in your solution's pH will affect its strength. The most affective is a pH of 5.5-6.2 never go higher than 6.5 or lower than 5.5 no matter what vegetables you are growing.
7. Use a TDS/PPM or EC meter to check the strength of your nutrient solution. If it is too strong, add water. If it is too weak, add a little fertilizer. [See Warnings] Make sure you re-test the pH after making changes.
8. Change/top-up the solution in your reservoir when the TDS/PPM meter shows it to be at or below that which the plants require.
9. A proper top-up nutrient should not be used more than 3 to 4 times between full nutrient changes. Do not use full nutrient for top-ups.
10. It is good practice to have a nutrient reservoir as large or larger than the empty volume of the tub(s)/container(s). For example if a 20L tub is used then at least 20L of nutrient should be used, preferably more, twice as much is a good minimum. The volume of the growing medium not with standing in the volume calculations. The largest size nutrient reservoir (within reason) that can be implemented is better.
11. No particular time period should be applied to nutrient life as its life is dependent on is volume and the requirements of the plants as well as the plant's transpiration rate, all of which vary greatly
12. When the nutrient is considered past its useful life it can poured on dirt grown plants.
13. Hydroponic gardens grow better outside, but local weather conditions may affect it and should be taken into account. When growing outside all forms of falling water should be prevented from falling on the garden and so diluting the nutrient solution. # When growing inside provision of suitable lighting may be required.

Tips

• Tap water may contain chemicals which can adversely affect your plants. If you can smell chlorine or are unsure it is best to let your tap water stand for 24 hours prior to adding to your reservoir. Using chlorine remover for aquariums will add another unwanted chemical to your reservoir. By letting your water stand, you equalize the temperature of the water to that of the room, thereby making the water less likely to shock the plants' root system.
• A larger reservoir allows a greater capacity for buffering against PPM/TDS EC changes, plant water use and pH. It's best to aim to create the largest reservoir you can fit comfortably in the allocated area that you have.
• Oxygenation of the nutrient solution is paramount for nutrient uptake. Where possible, allowing return nutrient to splash back into the reservoir will suffice. If this is impracticable an aquarium air pump and stone rated for the size of your nutrient reservoir may be required.
• Make sure the fertilizer you use in a hydroponic system is complete. Match the solution's type and strength to your plants' needs.
• The number of nutrient flushes through the system per day will depend on what type of plants, their size/maturity, whether or not they are fruiting, and the air temperature and humidity.

Not less than two flushes per day (morning and evening)should be provided, but as many as one flush per two hours may be needed. A good guide is to watch the leaves, and when they show signs of wilting, add a flush at that time.

• It is a good idea to run plain water or 1/4 strength nutrient through the system during its regular timed flushes once or twice in between major or complete nutrient changes, to leach out any fertilizer buildup. Keep in mind this will weaken your prepared nutrient mix so a re-test and adjustment will be in order after a plain water or 1/4 strength flush.
• Keep your nutrient solution temperature between 70/78°F-21/25C. These are ideal figures, but readings slightly over and under as low as 12C 53F will work, however plant growth may be slower for lower temperatures.
• A lot of water treatment facilities have changed from Chlorine to Chloramine. They are doing this because it is cheaper due to the fact that Chloramine does not evaporate out of the water like Chlorine. If you ask the water company it "evaporates in 2 or 3 days" but with some online research you'll find many opinions that "it does not evaporate but breaks down into possibly harmful bi-products" The bottom line is you need a water filter that is capable of removing Chloramines. Standard RO is not enough, you still need to purchase a Chloramine removing pre-filter for your RO system.

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