Water & Irrigation — Pumps

Nine pumps from AquaKing, and the choice is not about the largest number but about what you want the water to do. Circulating it within one tank is a different job from taking it somewhere else, and the pumps for each are built differently.

Circulating: the HX range

Standing water separates. Nutrients settle out, oxygen disappears and the top layer ends up with a different composition from the bottom, after which you measure in one part and water from the other. The HX-1500 at 400 l/h, HX-2500 at 1000 l/h and HX-4500 at 2000 l/h are the sizes for this: choose on your tank's volume, because what matters is how often the contents turn over, not how fast they are taken somewhere.

Moving it: the Q range

For transferring and emptying there are submersibles at Q2007 3600 l/h, Q2503 5000 l/h, Q4003 7000 l/h and Q5503 11,000 l/h. Watch the connection, because it decides which hose fits and where it sits: the Q2007 has a top connection for 20/25 mm, the Q4003 and Q5503 a side connection for 25/30 mm. The wrong size is not a disaster but it is an extra adapter in a line where you would rather not have one.

Two that do something else

The Q2001 flat-suction pump at 2800 l/h draws down to a water level of about 2 mm. That empties a tank, a table or a flooded floor properly, instead of leaving a last layer you end up removing with a cloth. The Q800103 at 5500 l/h delivers pressure rather than volume alone, with a top connection for 25 mm hose, and you need that as soon as you have to pump upwards or work against resistance in the line.

Litres are half the story

The litres per hour figure applies at free outflow. If the pump has to work upwards, to a raised tank or to a table, output falls with every metre, and at its maximum head it delivers nothing at all. So look at both. Where the water is going is under Growing Systems, and the tanks it comes out of under Water Tanks.

Frequently asked questions

Can a submersible pump run dry?
No. These pumps are cooled by the water, so one that empties its tank and keeps running damages itself. Stay with it for the last stretch, or use the flat-suction pump, which is built to go down to almost nothing.

Which pump for an AutoPot or Blumat system?
None. Those run on gravity and need no pump; raising the tank does the work. A pump is at most handy there for filling or emptying the tank.

Why does less come out than the box says?
Height and resistance. Every metre of lift, every bend and every metre of hose costs output, and a hose narrower than the connection costs the most.