Net water, not tank rating. Use the Tank Volume calculator if you have not measured it.
Vodka, vinegar, or NoPox to drive nitrate and phosphate down, with the ramp schedule that keeps it safe.
| Week | Daily dose | Note |
|---|---|---|
| Week 1 | 0.30 mL | Start here, whatever the nitrate reads |
| Week 2 | 0.60 mL | Step up only if the tank is clear |
| Week 3 | 0.90 mL | Step up only if the tank is clear |
| Week 4 | 1.20 mL | Step up only if the tank is clear |
| Week 5 | 1.50 mL | Step up only if the tank is clear |
| Week 6 | 1.80 mL | Step up only if the tank is clear |
| Week 7 | 2.10 mL | Step up only if the tank is clear |
| Week 8 | 2.40 mL | Step up only if the tank is clear |
Carbon dosing feeds bacteria that take up nitrate and phosphate into their own cells. A skimmer then has to remove those bacteria, so a well running skimmer is a requirement rather than an option. Without export, the nutrients come straight back when the bacteria die.
week 1 dose = 0.001057 mL/L × 284 L = 0.30 mL/day, ceiling 5.47 mL/day
Carbon dosing works by supplying a carbon source that bacteria can use but algae cannot. The bacteria multiply, taking nitrate and phosphate into their cells, and a skimmer removes the bacteria along with the nutrients they hold.
The published vodka schedule starts at 0.1 mL per 25 US gallons per day and steps up weekly. This page works in mL per litre, which is the same figure: 0.00106 mL per litre per day to begin with, rising to a ceiling near 0.019.
Ramping slowly matters more than the final number. Going straight to a full dose feeds a bacterial bloom faster than the skimmer can remove it, the water turns milky, and oxygen drops. Every week at the same dose without a bloom earns the next step.
Vinegar delivers the same carbon at 8.2 times the volume, because 5 percent acetic acid holds far less carbon per millilitre than 40 percent ethanol. It is cheaper, gentler, and easier to dose accurately, at the cost of a larger reservoir.
The skimmer is not optional. Carbon dosing without export moves nutrients from the water into bacteria and then back into the water when those bacteria die. A tank with no skimmer gets a bacterial bloom and no nutrient reduction.
Both nutrients have to be present. Bacteria need nitrogen and phosphorus in a rough ratio, so a tank with nitrate at 25 and phosphate at zero will stall, and the nitrate will not move until phosphate comes up. This surprises people who have been running phosphate media hard.
Watch for what going too far looks like: cyanobacteria films, a bacterial haze in the water, corals that look thin and pale, and dinoflagellates. All of them mean back off rather than push harder.
Stop ramping the moment nitrate starts falling. The goal is a controlled reduction over weeks, not zero by Friday.
Sources: Vodka Dosing Distilled (Reefkeeping 2008) · Reef Central vodka dosing table · Red Sea Algae Management manual (PDF) · Tropic Marin NP-Bacto-Balance