DRAK pH/CH-Minus - pH and KH easily and quickly lowered

Comfortable and safe decrease of the water's carbonate hardness in fresh water

A lot of fishes and plants whose home consists of soft, well sour water are more comfortable with a lower carbonate hardness (CH). The total hardness (TH) is relevant only in rare cases.

With DRAK pH/CH-Minus you have a simple and easy possibility to drop the carbonate hardness permanently without the purchase of complicated and complex equipment.

In doing so we use the effect in water of every stronger acid than carbonic acid transforming (Hydrogen)Carbonates to carbonic acid. The desorption of that carbonic acid (CO₂) volatilizes after some time and fertilizes the plants in the meantime, too.


Please find out first the pH-value and the carbonate hardness of your aquarium water with commercial tests or in case of pH with a pH-meter.
Please inform yourself of the aspired target value using literature before using DRAK pH/CH-Minus

  1. When the pH-value is over 7.0 and the CH over 6° dCH put 10 ml DRAK pH/CH-Minus to 40 l water into the aquarium.
  2. When the pH-value is lower than 7.0 and / or the CH is lower than 6° dCH put max. 2 - 4 ml DRAK pH/CH-Minus to 40 l water into the aquarium.

Measure the pH-value and CH the next day again. When needed add DRAK pH/CH-Minus once more.


The pH/CH-reduction must be performed step by step. The daily max. dose must not be transcended. Otherwise you risk damaging your plants and fishes because of the huge development of CO₂. Please put the solution thinned with aquarium water (min. 10 times as much) slowly into the aquarium where there is enough water movement to make sure an immediate mixture with the whole aquarium water.

Especially when the carbonate hardness is higher than 10° dCH you have to put the DRAK pH/CH-Minus into the water for several days to reach the wanted lowering.

As empirical formula you have to deal with a pH lowering of about 0.3 units when you half the CH with equal concentration of CO₂.


DRAK pH/CH-Minus contains about 5.1 % sulphuric acid

Per liter sufficient for about 3,000 HL (hardness liter) - this means you can lower the CH of 600 l water for about 5° dH with one liter.


Possible Dangers

  • Keep out of reach of children!
  • Attention: reacts very acidly
  • Please use protection goggles and safety gloves


Signal word: Danger

Danger warnings

H290 May be corrosive to metals
H314 Causes severe skin burns and eye damage
H319 Causes serious eye irritation

Safety information

P260 Do not breathe dust/fume/gas/mist/vapours/spray
P280 Wear protective gloves/protective clothing/eye protection/face protection
P301 + P330 + P331 IF SWALLOWED: Rinse mouth. Do NOT induce vomiting
P303 + P361 + P353 If on skin (or hair): Take off immediately all contaminated clothing. Rinse skin with water [or shower]
P305 + P351 + P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing
P308 + P313 IF exposed or concerned: Get medical advice/ attention

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18 February 2014 08:18

In der Testphase, bisher gute ...

In der Testphase, bisher gute Werte

4 April 2015 08:15

alles gut gelaufen...

alles gut gelaufen

3 August 2017 15:50

Ich stelle damit eine Mischung...

Ich stelle damit eine Mischung von 100 l Osmosewasser und 100 l Leitungswasser ein. Bei 180ml pH/KH-Minus Zusatz ergibt sich reproduzierbar sicher eine KH 3 und eine GH 6 bei unserem harten Leitungswasser. Mache das seit Jahren. Inzwischen messe ich die Werte im Reservetank nur noch stichprobenhaft, weil die Methode immer das gleiche Ergebnis liefert.


20 ml Dispensing Beaker for Screwing
Plain dispensing system (capacity max. 20 ml) for measuring the necessary amount of fertilizer or adding water treatment.

30 ml Canister pump
Dosing pump for 3 and 5 litre canisters

Metering valve with venting for canisters
With vent for 3 and 5 litre canisters

1 ml Dispenser pump
For measuring fertilizer or adding water treatment


Checking water values

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PRODACtest pH - Operating range 4.5 - 9.0
Determination of pH value. For fresh and sea water. Up to 130 applications.

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PRODACtest KH - Carbonate hardness test
Determination of carbonate hardness (CH). For fresh and sea water.

Zoobest Alpha Test Carbonate Hardness - CH
Determination of carbonate hardness (CH). Suitable for fresh and sea water.


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