Deciding what type and size of machine to use is always difficult. Virtually all the machines on the market made in the USA are reliable machines that work well and give trouble free performance.
Machines come in two main types. Jet agitated and mechanical agitated. Jet machines use a powerful flow to circulate the slurry and quickly mix materials.
The advantages of jet machines are that they have fewer parts and are reliable. They are easier to run than some mechanically agitated units. They generally require a smaller investment. Jet units are best used with paper mulch, pourable mulches and wood/paper blends. Jet units are good choices for someone doing residential and commercial installations.
Mechanically agitated units use one or more paddles to mix the material and a centrifugal or gear pump to pump out the slurry. Mechanically agitated units will handle a wider range of materials and a little thicker slurry. Any type of paper, wood, blend or erosion control material can be used in a mechanically agitated hydro seeding unit. Units are available with both gear and centrifugal pumps.
Some people feel that a centrifugal pump has advantages for spraying from a tower and gear pumps may have some advantages for spraying through long lengths of hoses. Gear pumps perform excellently but may require a little more maintenance than centrifugal pumps.
Mechanically agitated units are good choices for residential and commercial lawn installations and for erosion control work. What size of unit to buy Most everyone who HydroSeeds wishes they had the next size bigger. Units are manufactured from 50 gallons sizes to 4000+ gallon sizes.
For residential and commercial installations many feel a 300 (+/-) gallon unit is the minimum although some have done well with smaller units. The larger the unit the more you can seed without refilling.
Some people are able to do larger jobs effectively with a smaller unit and a nurse tank which can allow an operator to seed larger areas fairly quickly. Some of the factors that should be considered are the size and type jobs that are expected, the equipment budget, the transportation equipment available and the importance of efficiency.