Both jet and mechanical agitated hydroseeders have their advantages and disadvantages.
The biggest advantage to mechanical agitation is that you can mix varieties of mulch that simply cannot be mixed in a jet agitated machine. While we successfully mixed 70/30 wood/paper blend mulch in our jet agitated units, we strongly urge our customers to stick with paper mulch. Mechanically agitated machines have almost no limits on mulch types that can be used which can mean more coverage per gallon to the equivalent jet machine.
Mechanically agitated machines are much more expensive than jet machines, so much so that the up front investment for a mechanically agitated machine may take years to repay.
Our jet machines are virtually maintenance free. Poly tanks don’t rust or require expensive re-coating. No moving parts besides the pump impeller means little or nothing to go wrong versus a mechanically agitated machine that is often made of steel and has lots of moving parts, seals, and bearings to maintain.
VSI Hydroseeders typically do not clog when following the provided mixing instructions and do not require thorough clean outs after each use. Simply running some water through it is enough when finished using the machine for the day. Mechanical units and the type of mulches often used in them must be cleaned out promptly to avoid plugging the spray lines and the pump. Even trips between jobsites can prompt lines to plug in a mechanically agitated machine.
Mechanically agitated hydroseeders typically have capacities much larger than jet machines. If your goal is hydroseeding a large number of acreage every day, then mechanical agitation might be the right way to go. Our line of jet machines go up to 400 gallons and are designed more towards the smaller, niche market or doing turf touchup after plowing or landscape work where larger machines are not needed.