How to Dose Your Reef Aquarium Like a Vet in 2025 🧪🐠 | Expert Dosing Guide by Dr Duncan Houston
In this article
How to Dose Your Reef Aquarium Like a Vet in 2025 🧪🐠
Reef keeping in 2025 is more rewarding than ever—but keeping your calcium, alkalinity, and magnesium levels (CAM) stable is crucial to coral health and growth. I’m Dr Duncan Houston BVSc, and I’m here to guide you step-by-step on safe, effective dosing for your marine aquarium 🐚.
From understanding CAM consumption to setting up a dosing pump or hand dosing manually, this method is designed for beginners and seasoned reefers alike. Let’s break it down 👇
🧪 Step 1: Test Your Key Parameters
Start by measuring:
- Calcium (Ca): Vital for skeletal growth in corals 🧱
- Alkalinity (dKH): Maintains pH stability ⚖️
- Magnesium (Mg): Regulates Ca and dKH levels 🧬
If any values are too high or too low, proceed to Step 2. If everything is perfect—skip to Step 3.
🔧 Step 2: Adjust Your Parameters Safely
If your levels are:
- Too Low: Use your dosing supplement or the online reef dosing calculator to determine how much to add 🧴
- Too High: Allow parameters to equalize by minimal feeding and partial water changes 💧
⚠️ Always confirm with quality test kits before making major changes. Poor test accuracy is a common issue.
🛑 Step 3: Pause All Dosing for 7 Days
This “dry run” helps you understand how much CAM your tank consumes weekly. Just feed and care normally—but do not dose any supplements for a full week.
At the end of 7 days, retest your CAM levels 📊.
📉 Step 4: Measure the Drop in CAM
If CAM levels dropped, congratulations—your tank is using supplements and you're ready to calculate your dosing plan!
- Use the dosing calculator or product instructions to calculate the dose needed to restore levels 🧮
- Note down the required amount in mL or grams for a full correction
📆 Step 5: Start Dosing Safely
This is crucial—never dump the full dose into your tank at once. That’s a recipe for stress or shock 💥
- Take your weekly dose requirement
- Divide it by 7 to find your daily dose
- Double the daily dose for one week to compensate for ongoing usage 📈
- After 7 days, drop back to the original daily dose and maintain it 👌
🧠 Example: Hypothetical Dosing Formula
Let’s say you have a 500L reef tank:
- Day 1 Calcium: 350 ppm
- You buffer it to 425 ppm using your chosen product 🧴
- After 7 days: Re-test → 400 ppm
- Using the calculator, it tells you to dose 337.9 mL of Randy’s Recipe #1
- Divide by 7 → 48.27 mL/day
- For 1 week, dose 96.54 mL/day
- From Day 8 onward → dose 48.27 mL/day until next test
📈 Step 6: Weekly Testing & Adjustment
Reef tanks are living systems. As corals grow or as you add more, their demand for CAM increases 🌿
- Test your parameters weekly 🧪
- Adjust your dose volumes accordingly
- Reprogram your dosing pump as needed
🧰 Tools You Need
- Quality CAM test kits (Salifert, Red Sea, Hanna, etc.)
- Dosing calculator (link here)
- Reliable supplements (2-part or 3-part systems)
- Dosing pump (for automated precision) or graduated measuring tools
💡 Vet Pro Tips from Dr Duncan
- Label everything: Even experienced aquarists can mix up dosing jugs 🤯
- Don't trust just one test: Double-check if a result seems off
- Stir and shake: Always agitate supplements before dosing to ensure consistency
- Go slow: Small changes = healthy coral responses 🌈
🚫 Common Mistakes
- Overdosing after a big drop → causes stress or bleaching 😓
- Skipping tests → leads to inaccurate dosing
- Assuming all tanks consume CAM the same way → each system is unique 🧬
- Using old reagents → always check expiry dates!
📲 Need Help? Ask A Vet Can Guide You
If you're unsure about your results or your coral isn’t looking right, don’t guess—get help. Ask A Vet offers expert marine support from qualified veterinarians. We help diagnose, advise, and monitor your tank health remotely 💬🐠
Download the Ask A Vet app to get 24/7 reef support wherever you are!
🔄 Dosing Summary Checklist
- ✅ Test CAM levels initially
- ✅ Adjust if low/high
- ✅ Pause dosing for 7 days
- ✅ Re-test & calculate consumption
- ✅ Dose slowly over 1 week (double daily)
- ✅ Maintain daily dose after 1 week
- ✅ Test weekly and adjust based on coral growth
🏁 Final Thoughts
Reef dosing doesn’t have to be a mystery. With consistent testing, steady habits, and support from veterinary experts, your corals will thrive—and so will your confidence 🌟
Whether you're new to reefing or looking to dial in your dosing automation in 2025, following these steps ensures your marine system stays healthy, balanced, and vibrant 🌊
Need help interpreting your water test results or diagnosing coral stress?
Download the Ask A Vet app today and get direct access to fish and coral care professionals 🐠🩺
— Dr Duncan Houston BVSc
