2100 GPH Cyclone Pump for Ponds, Fountains, Waterfalls, and Water Circulation

The amount of flow (in gallons per hour) that you need for your waterfall is determined by the width of the weir (the surface over which the water flows). Do you want a trickling stream? Or a gushing Niagra Falls? What I did was to visit different pond supply companies in my area and look at some samples (they usually have one or more fountains or waterfalls on display) then measure the width of the waterfall and ask how many gallons per hour is the pump they are using. Based on internet sources and confirmed as I have described, 1,000 GPH per foot of weir width will give you a visible and pleasant but small stream - not really a gush and more than a trickle. 2000 gph per foot of weir gives an effect more like a mountain stream. I should have thought to Youtube this but, oh well.

The label on the pump only shows a rating for 110V. I attached a photo of the pump.

The rule of thumb is to circulate the volume of your pond between 1 and 3 hours. So with 100 gallons this pump will circulate your water 21 times in an hour. In other words, save some money and buy a smaller pump.

Probably your water feature has a recommended gallons per hour (GPH), so you want to match that up with the pump. Putting too much water through the fountain could damage the fountain or the pump, or create a jet-stream of water that will shoot down low flying birds ! <hehe>

No. First you need to decide what is your GPH needed to run your sprinklers, and there might be a pump that will handle that, but not this model. From the specification sheet the maximum lift for this model is 20' so the flow at that height will be only a trickle.