A guide to controllers like Apex and GHL, auto-dosing systems, pH/ORP monitoring, and alert configuration.
Key Takeaways
A guide to controllers like Apex and GHL, auto-dosing systems, pH/ORP monitoring, and alert configuration.
Coral tank management involves daily measurements and supplementation, which is a significant burden for busy aquarists. In recent years, advances in aquarium controllers and smart sensors have made it possible to automate many of these tasks. This article explains the specific methods and configuration tips for implementing automation and smart monitoring in coral tanks.
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Choosing Aquarium Controllers
Aquarium controllers are the core device for automation. Here's a comparison of major products.
Neptune Apex: The most widely used controller in North America. It can connect multiple probes for pH, ORP, temperature, and salinity, and allows real-time monitoring from a smartphone via the cloud. High expandability through module additions, with great programming flexibility
GHL ProfiLux: A high-precision German-made controller popular among European reef aquarists. Particularly excellent at automated KH (alkalinity) measurement and dosing, with powerful coordination with dosing systems
Hydros Control: A relatively new brand characterized by Wi-Fi connectivity and simple app operation. Good cost-performance as an entry model, with basic automation being sufficient
Selection tips: Choose based on the number of items you want to automate and your budget. For just pH and temperature monitoring, a ¥20,000–30,000 entry model is sufficient, but including KH measurement and dosing control requires investment of ¥100,000 or more
Building an Auto-Dosing System
Automating the addition of calcium, alkalinity, and magnesium dramatically improves water quality stability.
Choosing dosing pumps: Peristaltic pumps are available from manufacturers like Kamoer, GHL, and Jebao. Select a model with high precision matched to your daily dosing volume. Large errors can cause water quality fluctuations
2-Part System: The most common method, adding calcium and alkalinity solutions through separate pumps. Simultaneous injection causes precipitation, so schedule them at least 30 minutes apart
3-Part System: A 2-part system with added magnesium solution. Necessary for tanks with heavy magnesium consumption (SPS-dominated like Acropora and Montipora)
Automated Kalkwasser Addition: Adding kalkwasser (saturated calcium hydroxide solution) linked to evaporation compensation. Provides pH maintenance and simultaneous calcium and alkalinity supplementation
Calculating Dosing Amounts: Stop dosing for 2–3 days, measure the rate of parameter decline, and calculate daily consumption. Divide that amount by 24 and dose hourly for stability
Calibration: Once monthly, measure the actual ml output in one minute from your dosing pump for calibration. Tubing degradation gradually changes output
Real-Time pH and ORP Monitoring
Constant pH and ORP monitoring is extremely effective for early detection of water quality issues.
Importance of pH Monitoring: The ideal pH for coral tanks is 8.0–8.3. If pH drops too much at night due to CO₂ accumulation, it negatively impacts skeleton formation in SPS like Acropora. In contrast, LPS like Fungia and Lobophyllia tend to have higher tolerance to pH fluctuations. Real-time 24-hour trend tracking lets you understand daily variation patterns
Automated Response to pH Drop: If pH falls below 7.9, automatically increase kalkwasser dosing or run ventilation fans to expel CO₂
ORP Monitoring: ORP (oxidation-reduction potential) indicates oxidative strength in the tank, with 300–400 mV being the ideal range for coral tanks. A sudden ORP drop suggests heavy organic influx or bacterial bloom
Probe Maintenance: pH probes require monthly calibration (2-point calibration at pH 4.0 and 7.0). Keep calibration solutions sealed in a cool dark place and use within 3 months of opening. Probe lifespan is 1–2 years
Salinity Sensor: Linked with auto top-off systems to prevent salinity rise from evaporation. The ideal setup automatically adds RO water to maintain 1.025 specific gravity
Alert Settings and Notification Systems
The true value of automation is "being immediately informed of problems."
Temperature Alerts: Send push notifications to your smartphone when outside set ranges (e.g., 24–27°C). Directly leads to early detection of heater failures or chiller shutdown
pH Alerts: Issue warnings at pH 7.8 or below or pH 8.5 or above. pH abnormalities often signal other problems, so this is a top-priority setting
Water Level Alerts: Linked with sump water level sensors, notifies when abnormally low (clogged piping, pump failure) or high (drainage issues, overflow)
Power Failure Detection: UPS-connected controllers can detect outages and send notifications. You can assess the situation even away from home and decide if you need to rush back
Alert Tiering: Setting all alarms to the same priority causes alert fatigue. Classify rapid temperature or pH changes as "emergency" and gradual changes as "warning"
Redundancy: Cloud notifications won't arrive if your Wi-Fi router or internet connection fails. SMS notifications or local alarms (buzzers) are recommended as backups
Auto Top-Off (ATO) Systems
Auto Top-Off, which automatically replenishes evaporated water, is the highest cost-benefit automation.
How ATO Works: Install a water level sensor in the sump, and when water level drops, RO water is automatically pumped in. This minimizes specific gravity fluctuations
Safety Features: To protect against sensor failure where the pump won't stop, always install a physical backup sensor like a float switch. Excessive top-off causes dangerous specific gravity drops for corals
RO Water Tank Capacity: Prepare a tank that can cover one week of evaporation. For 60 cm tanks, 5–10 L is typical; for 120 cm tanks, 20–40 L
Combined with Kalkwasser: Dissolving kalkwasser in your ATO RO water allows simultaneous calcium and alkalinity supplementation during top-off. However, adding high-concentration kalkwasser all at once causes pH spikes, so set it to dispense slowly in small amounts
Implementation Steps and Costs
Gradual implementation lets you control initial investment while experiencing benefits.
Step 1 (Budget ¥10,000–20,000): Implement ATO (auto top-off) system. Greatest impact with major daily workload reduction
Step 2 (Budget ¥20,000–50,000): Add dosing pumps. Automated calcium and alkalinity addition stabilizes water quality
Step 3 (Budget ¥30,000–100,000): Add controller and pH probe. Real-time monitoring and alerts dramatically improve peace of mind
Step 4 (Budget ¥100,000+): Full system (automated KH measurement, ORP monitoring, lighting control, flow control integration). At this stage, daily routine work reduces to just weekly water changes and visual checks
Get Your Corals from BreederDirect's Automated Systems
At BreederDirect, you can purchase corals directly from breeders who maintain them in automated systems. Many breeders use controllers and dosing systems, and it's recommended to ask about automation know-how when purchasing. Once you've established a stable environment, explore BreederDirect to find your ideal corals.
