Solo Backpack Sprayer Deluxe 4 Gallon with Piston Pump

Qty Price
1 – 2 $119.99
3 + $109.99
Item # 425D
Ship Weight 11.60 lbs
Stock Status Out of Stock

4 gallon high-density polyethylene tanks with ultra-violet inhibitors allow for unmatched durability and ultra-violet protection.

Large 4.25-inch opening for easy filling and cleaning. Shut-off valve and wand with an overall length of 28-inch for hard-to-reach places. Padded shoulder straps for greater comfort.

The industry standard. Chemically resistant Viton® seals for long life and durability. The 425D is capable of producing a wide pressure range of up to 85 psi. Easily and effectively handles disinfectants, fertilizers, herbicides, pesticides, and formulations for tree, shrub and plant protection.

Deluxe Models: Both Piston and Diaphragm sprayers are available in Deluxe form which include addition of a 4-position adjustable pressure cylinder, fold away pump handle, brass adjustable nozzle, carry handle and a waist belt.

Product Information


  • 4 gallon
  • Fill neck opening 4.5in
  • Piston pump
  • 90psi working pressure
  • Fold away handle
  • Padded straps
  • Adjustable brass nozzle
  • Dry weight 14 lbs

Product Features

  • Sprayer has wide mouth for easy filling.
  • Padded shoulder straps for carrying comfort.
  • Pressure regulator inside tank on pressure cylinder to set pressure to 4 settings.
  • Fold away handle to allow for easy storage.
  • Deluxe model includes brass adjustable nozzle


Manufacturer supplies a one year warranty.

Image Gallery


QUESTION: Will the plastic material last?
ANSWER: Only high density polyethylene is used. The material is chosen for high molecular weight, high impact strength, and excellent resistance to chemicals and stress. Ultraviolet inhibitors are used in the material to reduce deterioration caused by sunlight.
QUESTION: Can I use weedkiller and insecticide in the same sprayer?
ANSWER: In theory you can, if the sprayer is thoroughly cleaned out with ammoniA: water solution of 1:25. In practice, the use of both types of chemicals in the same unit is not recommended as the risk to the plants can be high. Use caution when handling any type of chemical and when cleaning your sprayer.
QUESTION: Does the unit require constant pumping?
ANSWER: The well-designed level action greatly reduces the pumping effort. The pressure cylinder within the tank has a hydraulic effect. Liquid from the pump compresses air in the pressure chamber which allows irregular pumping action, yet results in steady spray at the nozzle.
QUESTION: Does the pressure gauge set the pressure?
ANSWER: The pressure gauge does not really set the pressure, it tells you at what pressure you are operating. Pressure is determined by pumping it.
QUESTION: Can you use bleach in this sprayer?
ANSWER: No, the vendor says it ruins the o-rings.

Customer Reviews

Review Summary (Based on 1 Reviews)

Overall Rating: 5/5

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from IN



The ability to control the pressure ( 4 possible pre-sets ) for the application is a real feature. You eliminate the common problem of "over spraying" applications. Another feature is the pressure gage visually shows you the spraying pressure while spraying. No guessing what the pressure is. The fold away handle is a nice feature when storing the sprayer. It eliminates having to take off the handle when storing the sprayer. The Solo owners manual is very complete. The manual incorporates a parts breakdown. I found the Solo customer service and technical people very willing/able to answer questions. I have written to Solo and suggested they incorporate a carrying handle in the sprayer tank cap. It would make it easier to handle/carry the sprayer. Also suggested they use decal numbers in the gallon levels that are cast into the tank. It would make reading the tank levels much easier.