NaDCC Dosing: How Many Aquatabs per Tank, Jerrycan and Tapstand?

One Aquatabs 67mg NaDCC tablet treats 8 to 10 litres of clear water with 30 minutes of contact time, per the CDC and Medentech instruction sheet. So a 20-litre jerrycan needs 2 tablets, and a 70 m³ Oxfam tank needs roughly 7,000 to 8,750. Filter cloudy water through clean cloth before you dose.

What strength is the tablet, and what does it treat?

Aquatabs work because their active ingredient is sodium dichloroisocyanurate (NaDCC), a US EPA-registered chlorine donor made by Medentech Ltd in Wexford, Ireland, per Medentech. The 67mg tablet is the field workhorse across East and Central Africa: one tablet, 8 to 10 litres of clear water, 30 minutes to act. Dose against the volume of the container you are actually filling, not the volume you intend to draw over a day.

How many Aquatabs 67mg tablets per volume?

The table below uses the rated 8 to 10 litres per 67mg tablet from the CDC and Medentech instruction sheet. Where a range is shown, dose toward the higher tablet count in hot, high-demand or longer-storage conditions so enough residual survives to the cup.

| Water volume | Container | Aquatabs 67mg tablets (clear water) |

|--------------|-----------|-------------------------------------|

| 10 litres | Small jerrycan / bucket | 1 |

| 20 litres | Standard jerrycan | 2 |

| 200 litres | Drum | 20 to 25 |

| 1,000 litres (1 m³) | IBC / small bladder | 100 to 125 |

| 11,000 litres (11 m³) | Oxfam T11 tank | 1,100 to 1,375 |

| 45,000 litres (45 m³) | Oxfam T45 tank | 4,500 to 5,625 |

| 70,000 litres (70 m³) | Oxfam T70 tank | 7,000 to 8,750 |

| 95,000 litres (95 m³) | Oxfam T95 tank | 9,500 to 11,875 |

Oxfam steel emergency tank capacities of 11, 45, 70 and 95 m³ are confirmed by the Oxfam Supply Centre. For bulk volumes this size, most teams switch from counting individual tablets to a measured stock-chlorine dose with calcium hypochlorite (HTH); the tablet figures above are the upper bound and a useful cross-check rather than the practical method at 70 m³.

Why does contact time matter?

Chlorine needs 30 minutes to inactivate pathogens before the water is safe to drink. Dosing the jerrycan and handing it over immediately defeats the treatment, so the 30-minute wait is part of the dose, not an optional extra. After contact, you are aiming to hold a free residual that survives storage: at least 0.5 mg/L after 30 minutes at the treatment point and at least 0.2 mg/L at the point of delivery, per the Sphere WASH standards. Test the residual in the home, not only at the tapstand, because heat and handling strip it faster than the textbook assumes.

What about cloudy or turbid water?

Turbidity is the single most common reason the dose above fails. Suspended solids shield pathogens and consume chlorine, so cloudy water must be filtered through a clean cloth before dosing, per the CDC and Medentech instruction sheet. The CDC guidance on making water safe in an emergency puts the household chlorine demand at roughly 2 mg/L for water below 10 NTU and around 4 mg/L for water above 10 NTU, so genuinely turbid source water needs more chlorine, not less. Where source water stays visibly cloudy after settling, a coagulant-disinfectant such as P&G Purifier of Water is the better tool than chlorine tablets alone.

Frequently asked questions

How many Aquatabs do I need for a 20-litre jerrycan?

Two Aquatabs 67mg tablets, because one tablet treats 8 to 10 litres of clear water in 30 minutes, per the CDC and Medentech instruction sheet.

How many tablets for a 70 m³ Oxfam tank?

Roughly 7,000 to 8,750 Aquatabs 67mg tablets at the rated 8 to 10 litres each, though at 70 m³ most teams dose with measured HTH stock chlorine instead of counting tablets. Tank capacity is confirmed by the Oxfam Supply Centre.

What is the active ingredient in Aquatabs?

Sodium dichloroisocyanurate (NaDCC), a US EPA-registered chlorine donor made by Medentech, per Medentech.

How long before the water is safe to drink?

Thirty minutes of contact time after dosing clear water, per the CDC and Medentech instruction sheet. Cloudy water must be filtered first.

Do I dose more for dirty water?

Yes. Filter turbid water through clean cloth first, and expect higher chlorine demand: around 4 mg/L for water above 10 NTU versus 2 mg/L below it, per the CDC guidance on making water safe in an emergency.

Specialized Logistics Solutions is an in-country distributor based in Juba, an authorised distributor for Aquatabs (Medentech/Kersia), P&G Purifier of Water, and Oxfam tanks (Butyl Products), and a UNGM-registered vendor (No. 380716). In the 2024-2025 South Sudan cholera response, SLS deployed more than 52 million Aquatabs 67mg NaDCC tablets, giving UN agencies and NGOs outbreak-scale dosing capacity rather than a catalogue number. Request a quotation from SLS to size and stock your chlorination programme.