ESV B-Ionic Nitrate — Purified Calcium Nitrate for Low-Nutrient Reef Tanks 16 oz to 1 gal

ESV B-Ionic Nitrate is a concentrated source of nitrate in the form of a highly purified calcium nitrate solution. Maintaining nitrate concentrations slightly higher than natural reef levels has been observed by many aquarists to be beneficial to coral health and coloration. This may be because higher nitrate levels compensate for the lack of planktonic food organisms and particulate organic nitrogen available to corals in the wild.

Raising nitrate without importing phosphate

When phosphate levels are already high, increasing food input becomes problematic when trying to raise nitrate — because food also imports phosphate. B-Ionic Nitrate solves this by raising nitrate without increasing phosphate.

Biological assimilation and denitrification convert the added nitrate into carbonate alkalinity, so there is no accumulation of sodium or potassium, two elements that are difficult to test for. Higher nitrate levels may also assist organic breakdown and prevent hydrogen sulfide formation in anoxic and anaerobic areas of rock and sand.

Concentration

1 ml per 20 gallons (76 L) of aquarium water adds 1 ppm nitrate.

Directions

• Start by adding 1 ml per 20 gallons (76 L) of aquarium water daily — 1 drop per gallon
• Each additional millilitre will add 1 ppm nitrate
• Test nitrate every 5 days and adjust the dose until your target level is reached
• Do not increase the dose by more than 1 ml per 20 gallons daily within a 5-day period
• The manufacturer recommends maintaining nitrate levels between 5 ppm and 10 ppm

These detailed directions come from the ESV product label. The manufacturer's website currently publishes only the concentration (1 ml/20 gal = 1 ppm); the dosing steps are preserved as printed on the original packaging and are reproduced identically by ESV distributors.

⚠️ Manufacturer's warning

May cause serious eye and skin irritation. Harmful if swallowed. Keep away from children. For aquarium use only — not for human consumption.

Available sizes

• 16 fl oz (473 ml)
• 32 fl oz (946 ml)
• 1 gallon (3,784 ml)

Our advice

These days, with the newer systems being more and more efficient, it happens often that tanks end up at zero or very close to zero nitrate. When that happens, we recommend trying to bring it up a bit and holding at least two, three, four. It helps the corals a lot, and the ecosystem in general.

— Stéphane, Aquarium ReefSolution

Rounding out your routine

• Salifert Nitrate Test Kit — essential: dosing is driven by testing, every 5 days
• ESV B-Ionic Calcium Buffer — the two-part calcium and alkalinity system from the same line, built to preserve ionic balance
• ESV B-Ionic Magnesium — magnesium free of nitrates, phosphates and chelating agents, designed not to disrupt ionic balance
• Seachem PhosGuard — to keep phosphate in check while you bring nitrate up

Frequently Asked Questions

Why add nitrate to a reef aquarium?

Modern reef systems — heavy skimming, refugium, algae scrubber, bacterial dosing — can become nitrogen limited. Nitrate is a necessary nutrient: at zero, corals brown out, pale, or stop growing. Maintaining a measurable level supports health and coloration.

Why not simply feed more?

Because food also brings phosphate. If your phosphate is already high, increasing feeding makes the problem worse. B-Ionic Nitrate raises nitrate on its own, without touching phosphate.

Does it unbalance the water like other nitrate supplements?

No. The nitrate is supplied as purified calcium nitrate: biological denitrification converts it into carbonate alkalinity, leaving behind no accumulated sodium or potassium, unlike other formulations.