Phos 400
Phosphorous Acid Derivatives are ideal for the Control of Pythium, Phytophthora, Fusarium and other Disease Causing Fungi in Hydroponics and other Cropping Situations. They also have a reputation for enhancing a plant’s ability to resist disease.
(This product is Not to be confused with Phosphoric Acid – which is used for pH control in hydroponics).
Pure Hydroponics stocks the brand Phos 400™ which is 40% (400g/L) of the active ingredient being a mixture of mono and di potassium salts of phosphorous acid (aka. phosphonic acid).
Pythium, Phytophthora and Fusarium can cause widespread damage to plants in a hydroponic system.
Good water treatment with products such as Oxine will remove these pathogens from the incoming water supply, however gnats, shore flies and similar insects can carry the fungi into a hydroponic system from flooded ditches, swamps and ponds where they breed. These are the source areas where the above-mentioned pathogens are most prevalent.
The use of Phos 400™ is an effective treatment for targeting these water borne pathogens.
Phos 400™ can be applied in three ways:
– As a foliar spray
– As a nutrient solution tank additive
– As a soil or media drench
Available in:
Phos 400 500ml – $17.40 + GST
Phos 400 1 Litre – $26.70 + GST
Phos 400 5 Litre – $65.00 + GST
Phos 400 20 Litre – $193.00 + GST
200 Litre NZ$P.O.A
Dose Rates:
Foliar Spray – 250ml per 100 litres of spray solution plus surfactant as needed to wet the leaf. Apply every 3 – 4 weeks as a maintenance spray or every 2 weeks if root disease infection is present (Pythium etc).
NFT Tank Dose (Maintenance dose)
100ml per 1000 litres every 3 – 4 weeks
NFT Tank Dose (When Pythium is present on roots)
300ml per 1000 litres of tank solution every 2 weeks, then reduce to 100ml per 1000 litres every 3 – 4 weeks once under control.
Batching Tank Dose (Maintenance dose) (Run to Waste Systems)
100ml per 1000 litres of tank solution every 3 – 4 weeks
Drain batching tank down until there is enough solution in the tank for 1 – 2 days of feeding then add the Phos 400. Do not allow this to be further diluted until the solution has all been fed out to the crop within 1 – 2 days.
Batching Tank Dose (When root disease is present) (Run to Waste Systems)
300ml per 1000 litres of tank solution every 2 weeks
Drain batching tank down until there is enough solution in the tank for 1 – 2 days of feeding then add the Phos 400. Do not allow this to be further diluted until the solution has all been fed out to the crop within 1 – 2 days.
Then reduce to 100ml per 1000 litres every 3 – 4 weeks once under control.
Always slowly drip the Phos 400 into the tank via a bucket with small hole in the bottom to ensure good circulation and mixing.
For all hydroponic system types: In situations with automated nutrient dosing controllers are used, it is best to turn the controller off so it can’t dose any nutrient stock solutions while the tank is being prepared. Then dilute the nutrient solution strength with water, add the Phos 400, let the readings stabilise, then reactivate the dosing controller so it can top up the solution strength to normal levels. This avoids exceeding your EC and pH setpoints. The same applies to growers who manually dose their tank with nutrient stock solutions.
Once the readings are within the deisred range the solution can be fed to the crop.
Do not exceed the recommended dose rates or frequencies listed above.
Never apply seaweed extracts etc to hydroponic crop foliage as it can increase the risk of bacterial infections.
Strawberries: When plants are set out, which have been previously grown in soil, they can be soaked overnight in Phos 400 using 30ml/100L as a precaution to reduce incidence of root carried infections.
Phosphorous Acid Derivatives such as Phos 400™ are cleared for safe use on all vegetable crops in New Zealand. Please discuss usage on your particular crop with Pure Hydroponics before ordering.
Please see the attached PDF article below for a more detailed explanation of this product and its applications.