Why Bother?

There are many reasons why you should religiously clean your spray tanks and lines between products. To avoid product hardening which can come off in subsequent sprays and block lines and filters. 

  • To avoid corrosion or other chemical damage to gear.
  • To ensure there are no residues of one chemical and another.

For instance,  if you want to spray out a paddock with glyphosate and then spray another paddock with seaweed,  you don’t want glyphosate mixed in with the seaweed or in your lines.  The fist product out of the line, in this instance, is likely to be glyphosate and coming out at the normal rate to kill.  After that you would have a weaker solution but it still may be enough to cause damage.

Cleaning Objectives

When cleaning your tank and line you have two main objectives. 

  • Diluting the active ingredient below levels that will cause damage or removing herbicide totally.
  • Deactivating any herbicide.

Where to Clean up

Clean up in an area where: 

  • Access by livestock, pets and children is restricted.
  • There is no risk of run-off into streams or ponds.
  • You avoid contamination of crops.

The ideal is to spray back in the area recently sprayed but if this is not possible waste ground is ok as long as you can prevent run-off into streams or ponds and you have diluted sufficiently that the effective application rate is less than the recommended rate on the products label.   

Cleaning Products

There are a wide range of cleaning product available ranging from domestic to commercial cleaners.  Commercial cleaners apart from cleaning will often deactivate some herbicides by raising the pH.  Other herbicides are deactivated using chlorine based bleaches which raise the pH.

AGAIN – ALWAYS CHECK THE SPECIFIC PRODUCT LABEL

WARNING: Ammonia or products containing ammonia such as many fertlisers should NEVER be mixed with chlorine based cleaners and sanitisers. 

Dangerous chlorine gas can be produced.

Good Cleaning Practice

         IN ALL CASES READ THE LABEL AND AT A MINIMUM ADHERE TO THE EQUIPMENT CLEANING AND DISPOSAL REQUIREMENTS ON THE LABEL.

Athough many of the principles are the same for all herbicides some specific herbicides have specific requirements so it is really important you read the label.  If you don’t have the original container with you all our product labels are available on our website.

·        Refer to NZ Standard 8409:2004 – Management of Agrichemicals.  If you don’t have a copy you can buy a copy here:

o   https://shop.standards.govt.nz/catalog/8409:2004(NZS)/scope

o   The full text is available here but it is not formatted so it is not an easy read.  https://archive.org/stream/nzs.8409.2004/nzs.8409.2004_djvu.txt

·        Check your gear carefully

o   Clean or replace screens

o   Check for cracked hoses which can catch residues.

o   Same with places like U or L-bends etc. where residues can accumulate and be trapped.

o   Wash and clean the inside of any lids and the inside of the tank at the top.  This often gets overlooked but product will slosh up in these areas.

o   Pay more attention to plastic tanks which are generally harder to clean than stainless tanks.

·        Never leave your gear sitting around dirty overnight.  Even if you are spraying with the same chemical the next day you need to flush the spray system as a minimum.  If other chemical or products will be used then a proper clean is required.

·        Empty the tank and rinse really well on the inside of the tank with water.

·        Spray water through the spray nozzles for 1-2 minutes.

·        Fill the tank with water and add cleaning agents if required.  Refer to the product label or standard NZS8409:2004 to establish what, if any, cleaning products are required or recommended.

·        Spray the cleaning solution through the lines and the nozzles back into the spray tank if possible and leave overnight if practical.  If not leave for at least 2 hours to allow the cleaning products to work.

·        Empty the tank – spraying through the spray nozzles and then rinse the tanks and lines with clean water.