Calculator
Example Data Table
| Net tank volume | Starting dose | Maximum daily guide | 500 ml bottle yield |
|---|---|---|---|
| 100 L | 5.00 ml/day | 25.00 ml/day | 100.00 days |
| 250 L | 12.50 ml/day | 62.50 ml/day | 40.00 days |
| 400 L | 20.00 ml/day | 100.00 ml/day | 25.00 days |
| 750 L | 37.50 ml/day | 187.50 ml/day | 13.33 days |
Formula Used
Net volume: gross volume × (1 − displacement ÷ 100).
Starting daily dose: net liters ÷ 100 × 5 ml.
Weekly increase: net liters ÷ 100 × 2.5 ml.
Maximum daily guide: net liters ÷ 100 × 25 ml.
Custom dose: net liters ÷ 100 × custom ml per 100 L.
Alkalinity trend dose: current dose + maintenance dose + correction dose.
Maintenance dose: daily drop ÷ effect per ml × net liters ÷ 100.
Bottle yield: bottle size ÷ recommended daily dose.
How to Use This Calculator
Enter the display tank and sump water volume. Choose liters or gallons. Add a displacement estimate for rock, sand, and equipment. Select the dosing mode that matches your goal. Use starting dose for a new plan. Use trend modes after several days of stable testing. Enter current and target values only when you know your daily use. Add bottle size and price when you want yield and cost estimates. Press calculate. Review the suggested dose below the header. Split the daily amount into small dosing events when using a pump. Test alkalinity and calcium often. Change the dose slowly.
Practical Reef Dosing Guide
Why This Tool Helps
A reef tank uses calcium and carbonate hardness every day. Corals, coralline algae, and clams take these elements from the water. A single balanced additive can replace much of that demand. Still, each aquarium consumes minerals at a different speed. This calculator gives a clear daily estimate. It also shows limits, bottle yield, and pump portions.
Start With Real Water Volume
The visible aquarium size is not always the true water volume. Rock, sand, pumps, and empty space reduce it. A small reduction can change the daily dose. Use the displacement field to create a safer net volume. This is useful for nano reefs and packed aquascapes.
Use Testing Before Chasing Numbers
Do not adjust from one test alone. Test at the same time each day. Watch the trend for several days. If alkalinity falls each day, the system needs more daily supply. If it rises, the dose is too high. Calcium often moves slowly, so compare weekly averages too.
Raise Levels Slowly
The trend modes include correction days. This prevents large jumps. A fast correction may stress corals. It may also hide the true daily demand. Set a longer correction period when the gap is large. Keep alkalinity, calcium, magnesium, and salinity in a stable range.
Plan Pump Schedules
Many reef keepers split the daily dose. Smaller additions can keep chemistry steadier. Enter the number of dosing events per day. The calculator returns the amount for each event. Calibrate the pump before trusting the schedule. Check the dosing line for air, salt creep, and clogs.
Track Yield And Cost
The bottle and powder fields help plan refills. They estimate how long your solution will last. This is helpful before vacations. It also helps compare ready solution and mixed solution. Keep a simple log. Record the dose, test values, livestock changes, and water changes.
FAQs
1. What does this calculator estimate?
It estimates a daily reef additive dose from tank volume, dosing mode, mineral trends, bottle size, and pump schedule. It is a planning tool, not a replacement for water testing.
2. Should I use gross or net tank volume?
Use net water volume when possible. Rock, sand, and equipment reduce actual water. The displacement field helps estimate that difference when exact water volume is unknown.
3. Why is there a daily maximum?
The maximum helps avoid aggressive additions. If your tank needs more than the guide, confirm test accuracy, check salinity, and review consumption before increasing further.
4. Which mode should beginners use?
Beginners should use the starting dose mode. Test alkalinity and calcium often. Increase slowly only when test trends show falling values.
5. Can I dose everything once daily?
You can, but split dosing is often steadier. A dosing pump can divide the same daily amount into smaller events across the day.
6. Why include alkalinity and calcium trends?
Trends show real aquarium demand. A daily drop helps estimate maintenance needs. Target gaps help estimate a slow correction over several days.
7. What if alkalinity rises after dosing?
Reduce the dose and test again at the same time daily. Rising alkalinity means the current addition may exceed actual consumption.
8. Does this replace regular reef testing?
No. Keep testing alkalinity, calcium, magnesium, salinity, and nutrients. Stable results are more important than a perfect calculated number.