Testing and adjusting the pH (acidity)
of the nutrients & water
The pH of the reservoir contents should be maintained at between 5.8 and 7.2.
Repeat pH tests frequently in hard water areas and weekly or fortnightly in soft water
areas. Use pH down if necessary.
To check the pH using the pH kit supplied:
1. Take a 2ml sample from the reservoir in the phial provided. Remember to switch off
the pump and heater before placing hands in the tank.
2. Add 2 drops of reagent to the phial.
3. Shake the phial gently and compare the colour with the test card to determine the pH.
The desired pH is anywhere between 5.8 and 7.2 if the test is green the pH is fine.
If the test shows blue (with no trace of green) it needs to be adjusted down. Use the pH
down and the pipette provided. Add the pH down sparingly (try 1ml at first until experience
tells you how much you will need). Allow the reservoir an hour to mix thoroughly then
re-test the acidity. Remember it is better having to repeat the process than to overdose
with the pH down.
If the test shows yellow, add tap water. If the yellow colour persists, or in the case of
accidental overdose of pH down, the solution should be changed as soon as possible.
In a small number of areas or if using 100% rainwater for the water supply the
test result may always be yellow. If this is the case contact Greenhouse Sensation™
for further advice.
1. Keep a diary noting your planting out dates and reservoir changes and recording all
top-ups required. The more water and nutrient used the better the plants are growing.
2. A weak acid solution is ideal for cleaning pump of lime-scale. Using the pipette
measure approximately 5ml of pH down for soft-water areas or 10ml of pH down for
hard-water areas and add to 1 litre of water in a suitable plastic container. At reservoir
changes run the pump in this container for 10mins. You can store this solution for
future use in a suitable container. Always label the container.
3. The ideal time to clean the pump is when you are carrying out a reservoir change.
Hints and advice
