250 ml, 500 ml, 2 L, 20 L
• Highly-effective alkalinity(KH)-increasing (”buffer”) solution.
• Helps increase pH stability in an aquarium by raising the alkalinity.
• Provides a source of carbonates, which make up the majority by weight
of aragonite, the mineral secreted by reef-building organisms as
• Continued addition raises pH until 8.3 is reached, at which point the
pH remains unchanged and the alkalinity alone increases.
• Over 50% stronger than most competing products.
• Free of phosphate, silicate, and organic material.
• Formulated by a marine scientist.
Alkalinity, also referred to as carbonate hardness or buffering
capacity, is essentially a means of quantifying the stability of pH in
a solution, such as aquarium water. Alkalinity is of extreme importance
in a marine aquarium, owing to the manner in which it influences pH. In
an aquarium, weak acids formed by oxygen respiration and the
decomposition of organic material gradually deplete alkalinity. If left
unchecked, the alkalinity drops below a critical level and pH begins to
fluctuate more wildly than is normally suggested (a daily pH shift of
+/-0.2 is normal in marine aquaria), causing stress to livestock.
Alkalinity is also depleted by reef-building organisms during the
production of aragonite (~60% carbonates by weight), and is therefore
very important for their rapid growth. Maintaining the alkalinity in
marine aquaria between 7 - 12 dKH (2.5 - 4.3 meq/L) will generally
maintain pH within the desired range. The rate at which alkalinity is
depleted in a reef aquarium is determined by the stocking density of
reef-building livestock, type of lighting, rate of water circulation,
and other biological, physical, and chemical conditions; therefore,
each aquarium will have different requirements for the rate of
alkalinity supplementation. Once the rate of alkalinity depletion in
the aquarium has been determined, the proper dosing rate of this
product can be easily calculated. It is recommended that a quality salt
mix with the proper (not augmented) alkalinity and concentrations of
major, minor, and trace elements be used to establish natural seawater
parameters in the reef aquarium, providing a stable ionic foundation on
which to build. For additional information on alkalinity and other
important aspects of marine chemistry for marine aquaria.
All Brightwell Aquatics liquid water care supplements are made with
purified water and high purity materials. We develop formulae for
aquaria based on empirical data, using observation and measurement
rather than theory.
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).
Advanced: Determine the alkalinity in the aquarium using an accurate
test kit before supplementing. 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). 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. Always try to maintain the
alkalinity within a range of +/-1 dKH. 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 daily dosing rate (preferable to
weekly dosing) for alkalinity maintenance: estimate the volume of water
in the entire aquarium system; divide the daily decrease in alkalinity
by 3.1 (when measuring alkalinity by dKH; divide by 1.1 when 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.
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
Note: If pH does not reach desired level when using this product as
directed, such as when gas exchange in the aquarium is insufficient,
addition of a pH-increasing product (i.e. Brightwell Aquatics pH+) may
be required. Follow manufacturer’s directions for using such a product
regardless of which one is used.
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.
Alkalinity (min) 11,760 dKH (4,200 meq/L)
Purified water, inorganic Bicarbonate, Carbonate, and Borate salts