Question 1

What size pump do I need for a vertical hydroponic tower?

Accepted Answer

Pump sizing depends on tower height (lift in PSI), plant count, and target recirculation rate. A 5-foot tower typically needs a pump rated for ~150 GPH at 5 ft of head. Our calculator picks the right pump from the curve, not from the rated free-flow number.

Question 2

How big should my reservoir be?

Accepted Answer

Roughly 0.75 gallons per leafy plant and 1.5 gallons per fruiting plant, plus 20% headspace. A 28-plant lettuce tower needs about a 25-gallon reservoir.

Question 3

Is the calculator free?

Accepted Answer

The Pump & reservoir sizing preview is free. The full suite (Feeding plan with EC/pH targeting and A+B doses, Crop plan with 26 crops and succession, Indoor lighting with PPFD/DLI, Pump schedule, Shopping list, Payback math, Outdoor seasons with frost + wind, and the downloadable Tower Plan HTML) is a one-time purchase of $34.99.