Dosing Pumps Explained: What They Do and Which to Buy in the UK

The Pumps That Keep Your Chemistry Stable

Once a reef tank starts keeping stony corals, there comes a point where water changes alone can't replace the calcium and alkalinity corals consume. Dosing pumps are small, precise pumps that automatically add measured supplements on a schedule, keeping parameters rock-steady.

What Gets Dosed

Alkalinity (dKH) — Consumed fastest. Most tanks need daily dosing, sometimes twice daily
Calcium (Ca) — Consumed alongside alkalinity as corals build skeletons
Magnesium (Mg) — Consumed more slowly. Some tanks only need weekly dosing

The approach: test consumption rates, calculate the daily supplement requirement, and program the dosing pump to deliver small, regular doses throughout the day.

What to Buy in the UK

Budget (£40–80):

Jebao DP-4 — Four channels, ~£50–60. What most UK reefers start with. Accuracy within 5–10% of target
Coral Box WiFi Dosing Pump — Similar price, WiFi control via app

Mid-range (£100–250):

Kamoer X1 Pro — WiFi-controlled, better accuracy. ~£60–80 per channel
Aqua Medic Reefdoser — Reliable, multiple channel options

Premium (£250–500+):

GHL Doser 2.1 — Exceptional precision, integrates with ProfiLux for automated dosing based on real-time readings
Neptune DOS — Extremely precise, integrates with the Apex controller
KH Guardian / KH Director — Automatically test alkalinity and adjust dosing in real-time. £400–600+

Common Mistakes

Dosing alk and calcium simultaneously — They can precipitate if mixed. Dose at least 15 minutes apart
Not calibrating — Tubing wears over time, changing flow rates. Recalibrate every month or two
Ignoring magnesium — Below 1200 ppm, calcium and alkalinity become unstable
Starting too early — A few soft corals don't need dosing. Water changes will maintain parameters until consumption outpaces them

Supplement Sources

Two-part solutions (Red Sea Foundation, Triton Core7, or DIY from bulk chemicals) are the most common approach. DIY using bulk calcium chloride and sodium bicarbonate costs about £20–30 for several months versus £40–60+ for branded solutions.

Browse dosing pumps from UK sellers — dosing pumps are commonly listed by reefers upgrading to more advanced systems.

What dosing setup are you running? DIY two-part or commercial solutions?