It is extremely important to clean the sprayer after every use and avoid the use of dry siphoning**.


Leaving solutions of any kind (nutrients, pesticides or compost teas) in the sprayer between uses, may:

  • damage the pump’s diaphragm,
  • clog the internal parts of the spray gun extension, and
  • void the Warranty.


To assist owners of Gro-King sprayers in maintaining optimum performance, and preserving the provisions of the Warranty, Gro-King sells Neutralizer, an effective granular cleaning agent that allows equipment to be used for spraying both pesticides and nutrients, without cross-contamination.




It is extremely important to clean the sprayer after every use.


  1.  Open the drain cap located on the rear of the tank.
  2.  Drain all unused solution from the tank and dispose of according to manufacturer’s directions. 
  3.  Fill the tank half-full with water and add ¼ cup of Neutralizer.
  4.  Dip a clean rag or sponge in the Neutralizer solution & wipe the inside of the tank
  5.  Flush the entire system (pump, hose and gun/injector) by locking the trigger in the “on” position for 5–10 minutes.
  6.  Drain all Neutralizer solution from the tank.
  7.  Refill the tank with clean water and flush the entire system again.
  8.  Lock the trigger in the “on” position and allow the system to “dry-siphon” briefly, in order to completely empty the pump and hose of water.
  9.  Remove the spray gun from the hose and pull the trigger. Any water remaining in the gun barrel will drain out through the Quick-Connect fitting at the bottom of the gun handle.
  10.  Place the spray gun on the hooks mounted on the side of the tank.
  11.  Coil the hose around the base of the tank.
  12.  The sprayer is now ready for storage in moderate temperatures until the next spraying session is scheduled.


**Dry Siphoning occurs when the pump is operated with the tank and hose empty of solution.

·      Dry Siphoning for extended periods of time is NOT recommended.

·      This pump has an “auto-shut- off” switch which is designed to prevent damage from the severe overheating that dry-siphoning can cause.

·      Please note that once the pump returns to ambient temperature it will automatically start up again.

·      This pump is exceptionally quiet so it is important to be sure it is manually shut off after each use.

More Information on Equipment Maintenance & Repairs

Gro-King is committed to providing excellent customer service. With proper care and maintenance, we have designed and built the TRW-115 to provide our customers with equipment that will deliver many years of cost-effective service.


To maintain your equipment within the terms of our Warranty, we include this helpful Operation Guide with purchase.  


To get sprayers working properly if any damage occurs outside the terms of our Warranty, we additionally offer phone consultations to assist with diagnosing the damage and selecting Replacement Parts. 


Please call Gro-King at 530-591-3923 for current pricing and more information.