Brightwell Aquatics

Alkalin8.3 - Liquid pH & Alkalinity Buffer

Grouped product items
500 mL Alkalin8.3 - Liquid pH & Alkalinity Buffer

SKU: 232760

In stock

Discontinued by Bulk Reef Supply

- +
2 Liter Alkalin8.3 - Liquid pH & Alkalinity Buffer

SKU: 232761

In stock

Discontinued by Bulk Reef Supply

- +

Brightwell’s Alkalin8.3 is part of a complete system for maintaining the major elements. The liquid forms are ready for use in a dosing pump and when coupled with CalcION and MagnesION, it is convenient and simple to maintain stable levels of carbonate hardness, calcium, and magnesium.



  • Alkalin8.3 is a multi-component buffer that regulates pH, unlike sodium carbonate
  • Supports stable aquarium chemistry
  • Eliminates pH and KH instability caused by poor salt mixes and ineffective buffering products.
  • Over 50% stronger than most competing products.
  • Free of phosphates, silicate, and organic material.


Available in Three Sizes

  • 250 mL
  • 500 mL
  • 2 Liters


Instructions and Guidelines

Basic: Shake product well before using. Add product at the maximum rate of 5 ml (1 capful) per 30 US-gallons daily until the desired alkalinity is attained, then dose daily or weekly as needed (see below) to maintain alkalinity between 7 - 12 dKH. When used in this fashion, 250 ml treats up to 1,500 US-gallons (5,678 L).



Always try to maintain the alkalinity within a range of +/-1 dKH. Daily dosing maintains a more stable alkalinity and pH (and a more natural environment) than dosing weekly, in which the alkalinity spikes just after dosing and then gradually decreases throughout the course of the week. Shake product well before using. 

Each ml of Brightwell Aquatics Alkalin8.3 will increase the alkalinity in 1 US-gallon (3.785 L) of water by 3.1 dKH (1.1 meq/L). 

  • Determine the alkalinity in the aquarium using an accurate test kit before supplementing. If the initial alkalinity in the aquarium is below 7 dKH (2.5 meq/L), add this product at the maximum rate of 5 ml per 10 US-gallons daily until the desired alkalinity is attained, then dose daily or weekly as needed (see below). 
  • For minor adjustments to alkalinity, add 5 ml (1 tsp) of Alkalin8.3 per 30 US-gallons of aquarium water as needed to maintain the alkalinity within the proper range. 
  • To determine the rate of alkalinity depletion once the desired alkalinity has been acquired, measure the alkalinity at the same time each day over a one- to two-week period. 
  • To determine the consumption rate of carbonate hardness in your system, measure the daily rate of alkalinity uptake (i.e. the decrease in alkalinity), estimate the volume of water in the entire aquarium system; then divide the daily decrease in alkalinity by 3.1 (divide by 1.1 if measuring by meq/L).
  • Multiply this number by the volume of water in the system to get the daily dosage required (ml) to maintain a stable alkalinity. 


Caution: Contains carbonate and bicarbonate salts; harmful if swallowed. If swallowed: give water, get medical attention. May cause eye or skin irritation. If in eyes, flush with water for 15 minutes, get medical attention. If on skin, wash thoroughly with water. Keep out of reach of children. Not for human consumption.



Purified water, inorganic Bicarbonate, Carbonate, Sulfate, Borate salts, proprietary ingredients


Problem pH Aquariums:  Aquaria with low circulation at the water’s surface, or in which a CO2-injected calcium reactor is being employed, or which are placed in an enclosed room with human and animal inhabitants giving off CO2 into the air, often have a depressed pH due to carbon dioxide build up. Certain measures, such as providing outside air to the skimmer intake port or other methods to control CO2 can bring pH in the aquarium back into a higher desired range without raising alkalinity to an unacceptable level. Changes to pH should be made very gradually, again to avoid stressing aquarium inhabitants.

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