Can the GARDENA pumps be used even at low volume (small hose cross-sections, drip irrigation systems, toilet flushing, etc.)?

Yes, in general, a small trickle of at least 90 l/h is sufficient to cool and lubricate the hydraulic parts of the pumps. Exception: GARDENA LCD Electronic Pressure Pumps require a flow of at least 140 l/h. Electronic Pump 5000/3 - 700 W (1413) Electronic Pump 850 E (1415) Garden Pump 3000/4 Jet (1422) Electronic Pump 6000/4 e (1425) Garden Pump 3000/4 (1426) Garden Pump 4000/4 (1428) Garden Pump 4000/4 Jet (1429) Garden Pump 4000/5 (1431) Garden Pump 4000/5 Jet (1432) Garden Pump 5000/4 (1433) Garden Pump 4000/4 Inox Multi 3 (1434) Garden Pump 4000/5 Inox (1435) Classic Petrol Engine Pump 9000/3 (1436) Garden Pump 5000/6 Inox (1437) Garden Pump 7000/5 Inox Multi 4 (1438) Garden Pump 3000/3 Jet (1442) Electronic Pressure Pump 3000/4 el. Plus (1480) Electronic Pressure Pump 4000/4i ep (1481) Electronic Pressure Pump 4000/4 el. Plus (1482) Electronic Pressure Pump 4000/5i ep (1483) Electronic Pressure Pump 4000/5 el. Plus (1484) Electronic Pressure Pump 5000/4i ep (1485) Electronic Pressure Pump 5000/4 el. Plus (1486) Electronic Pressure Pump 5000/5 Inox i (1487) Electronic Pressure Pump 5000/6 Inox e.p. (1488) Garden Pump 3000/3 Jet (1704) Garden Pump 3000/4 Jet (1706) Classic Garden Pump 3000/4 (1707) Garden Pump 3500/4 Jet (1708) Classic Garden Pump 3500/4 (1709) Garden Pump Set (1710) Garden Pump Set (1712) Garden Pump Set (1714) Garden Pump Set (1717) Garden Pump Set (1719) Comfort Garden Pump 4000/5 (1732) Comfort Garden Pump 5000/5 (1734) Premium Garden Pump 6000/6 inox (1736) Electronic Pressure Pump 4000/4 LCD (1763) Electronic Pressure Pump 4000/5 LCD (1765) Electronic Pressure Pump 5000/5 LCD (1767) Electronic Pressure Pump 6000/5 LCD (1769) Pressure Tank Unit 3000/4 (1770) Pressure Tank Unit 4000/5 (1772) Pressure Tank Unit 5000/5 (1774) Pressure Tank Unit 5000/5 Inox (1775) Pressure Tank Unit 3000/4 eco (1753) Pressure Tank Unit 4000/5 eco (1754) Pressure Tank Unit 5000/5 eco (1755) Pressure Tank Unit 5000/5 eco inox (1756) smart pressure pump (19106) smart pressure pump (19080) Electronic Pressure Pump (1757) Electronic Pressure Pump (1758) Electronic Pressure Pump (1759) Electronic Pressure Pump (1760)