Seachem Alkaline Buffer

A pH crash is almost never a pH problem. It is an alkalinity problem. KH is the reserve that absorbs the acid nitrification produces, and it is used up steadily – fastest in RO, rainwater and naturally soft tap water. Once KH reaches zero, pH falls off a cliff overnight.

Raise KH and pH holds itself. This product does that without adding phosphate, which matters because phosphate-based buffers hold pH very firmly but leave behind exactly the nutrient that feeds algae.

• Raises KH and pH together – one level teaspoon per 80 L adds about 2.8 dKH of buffering reserve
• Contains no phosphate – no phosphate dosed into a planted or display tank, so no feeding the algae you are trying to be rid of
• Targets a specific pH with Acid Buffer – published ratios for pH 6.5, 7.0, 7.5 and 8.0 rather than dosing blind
• Does not change GH – no calcium or magnesium, so shrimp and plant general hardness stays exactly where you set it
• Dry powder – no shelf-life clock the way a liquid buffer has, and the big packs are a fraction of the cost per dose

Seachem's published dose is 1 level teaspoon (6 g) for every 80 L, daily, until the pH you want is reached. Every figure below produces the same result: alkalinity up by 1 meq/L, or 2.8 dKH.

Dose once a day, not all at once. A tank sitting at 2 dKH that needs 6 dKH gets there over roughly two days, and the fish never feel the swing. Test before each dose rather than counting doses.

Worked from Seachem's own 6 g per 80 L dose. One full dose lifts alkalinity 2.8 dKH, so a tank needing three doses to reach target uses three times the volume shown.

Alkaline Buffer on its own pushes a tank above pH 7.6. To land on a number below that, Seachem publishes ratios to run it against Seachem Acid Buffer. Work out the Alkaline Buffer quantity you need for your target KH first, then divide it by the middle column to get the Acid Buffer quantity.

Seachem notes these ratios are set for RO and RO/DI water, which carries no buffering of its own. Tap water already holds some alkalinity, so expect to adjust the ratio to suit yours.

Suitable for: freshwater community and planted tanks · African cichlid and other hard-water setups · remineralising RO or rainwater · tanks whose pH keeps sliding down between water changes · anyone who wants firm pH without dosing phosphate.

Not suitable for: marine and reef tanks – Seachem Marine Buffer is the saltwater equivalent · raising GH, which this does not touch · soft-water species such as many wild-caught tetras, discus and Apistogramma, where high KH is the wrong target · emergency same-day pH correction, which stresses fish more than a low pH does.

• Keep the container closed and dry – the powder cakes if it draws moisture, which makes teaspoon dosing inaccurate
• Dissolve the dose in a cup of tank water before adding it, rather than tipping powder onto substrate or plants
• Test KH and pH before each dose. Counting doses instead of testing is how tanks overshoot
• Weigh rather than spoon on small tanks; a heaped teaspoon can be half again a level one

• Seachem Acid Buffer – the other half of the pair, and the only way to target a pH below 7.6
• Seachem pH & Alkalinity Kit – you cannot dose this product properly without reading KH
• Seachem Alkaline Regulator – the phosphate-buffered alternative, which locks pH harder at 7.1 to 7.6
• Seachem Marine Buffer – the marine tank equivalent
• The full Seachem range – water care, media and test kits

Sold with the manufacturer's shelf life; no separate warranty term is published for a dry buffer. Your rights under the Australian Consumer Law apply regardless and cannot be excluded. A safety data sheet is published by Seachem at sds.seachem.com. Ships as a standard parcel – it is a dry powder, not a dangerous good.

How much does Seachem Alkaline Buffer raise KH?

One level teaspoon (6 g) per 80 litres raises alkalinity by about 1 meq/L, which is 2.8 dKH. The change is the same at any volume as long as the dose is scaled to it.

Does Alkaline Buffer raise GH as well as KH?

No. It contains no calcium or magnesium, so it has no effect on general hardness. If your tank needs GH raised as well, that is a separate product.

Can I use Alkaline Buffer in a saltwater tank?

No. It is formulated for freshwater. Marine Buffer is the product Seachem makes for saltwater aquariums.

Why choose a non-phosphate buffer?

Phosphate-based buffers hold pH more rigidly, but they add phosphate to the water, and phosphate feeds algae. In a planted or display tank a non-phosphate buffer avoids trading a pH problem for an algae problem.

How do I hit a specific pH like 7.0?

Use Alkaline Buffer with Acid Buffer at the published ratio – 1 part Acid Buffer to 2 parts Alkaline Buffer for pH 7.0. Those ratios assume RO water, so adjust for the alkalinity your tap water already carries.

How fast should I raise pH?

Dose once daily and let the tank climb over several days. Fish handle a stable low pH far better than a fast correction, so slow is the safe way to arrive.