Water treatment
Water treatment for freshwater aquariums - valuable and durable
Water treatment is an important topic in aquaristics that should be given the utmost attention. For ornamental fish and other inhabitants of a freshwater aquarium, water is the element of life and should be treated appropriately in order to provide them with a habitat that corresponds as closely as possible to the natural conditions. We therefore offer a range of water treatment products to help you with this and to treat the quality of the water to suit the living organisms. We also offer vitamins and other additives.
Fresh water like in the tropics or simply purifying bacteria - we have it all
No matter which water conditioner you are looking for, you are guaranteed to find it in our aquarium shop. For example, if you are the proud owner of beautiful fish and creatures from the tropics, we recommend our Blackwater Aquatan product, which transforms your aquarium water into dark fresh water like in the tropics. Your tropical inhabitants are sure to love it. But other products from our water treatment range will also be to your satisfaction. Simple cleaning bacteria purify the water for your aquarium in a natural way. If you are a beginner or simply have questions about the individual products, you can contact us at any time by phone or e-mail. We are here for you!
Filter products

Average rating of 4.8 out of 5 stars
Sera Aquariaclear – Clear View for Your Aquarium Cloudiness in aquarium water can affect both appearance and water quality. Sera Aquariaclear reliably ensures crystal-clear water by effectively binding suspended particles and removing them in no time. Advantages of Sera Aquariaclear: Fast action: The bound particles are captured by the filter within minutes. Easy to use: Can be dosed directly into the aquarium water without complicated steps. Safe for all aquarium inhabitants: Free from harmful substances – no danger to fish, plants, or microorganisms. Using Sera Aquariaclear visibly and sustainably improves water quality. Especially in heavily populated or newly set-up aquariums, it helps eliminate cloudiness and create a healthy environment for the inhabitants. For aquarists who value clear and healthy water conditions, Sera Aquariaclear is the ideal solution.
Content: 0.1 Liters (€89.50 / 1 Liters)

Average rating of 4.7 out of 5 stars
KH / pH-plus – Optimal Water Values for Your Aquarium Carbonate hardness (KH) and pH value are crucial parameters for water quality in aquariums. With sera KH/pH-plus, carbonate hardness can be precisely regulated and kept stable over a long period. This is essential to maintain the biological balance in the aquarium and to create optimal living conditions for fish and plants. Advantages of sera KH/pH-plus: Stable water values: Prevents sudden pH fluctuations and protects against acid crashes. Easy to use: Can be dosed directly into aquarium water, fast-acting. Ideal for various aquarium types: Community aquariums: Recommended carbonate hardness 5 – 10 °dKH Malawi and Tanganyika cichlids: Optimal values between 10 – 15 °dKH Marine aquariums: Required values in the range of 8 – 12 °dKH By specifically adjusting the carbonate hardness with sera KH/pH-plus, the water remains stable and promotes the well-being of aquarium inhabitants. A constant carbonate hardness is especially essential for sensitive fish species and corals. The product offers a reliable solution for aquarists who want to control and improve their water values in the long term.
Content: 0.1 Liters (€79.50 / 1 Liters)

Average rating of 4.9 out of 5 stars
Sera O2 plus – Fast-acting oxygen supply for healthy aquariums Sera O2 plus offers an effective solution for oxygen deficiency and helps stabilize the biological balance in the aquarium. Thanks to its long-lasting effect, it prevents the formation of putrefactive gases and sustainably supports the self-cleaning capacity of the aquarium system. Optimal oxygen supply for a stable aquarium This special product ensures: Rapid oxygen delivery to prevent dangerous oxygen deficiency Long-term support of water quality by effectively binding putrefactive gases Improved self-cleaning capacity, helping to maintain biological stability Benefits for freshwater and marine aquariums The targeted oxygen enrichment promotes the health of fish, plants, and microorganisms and prevents stress caused by poor water quality. Technical details Fast-acting oxygen supply in acute situations Long-term effect that sustainably stabilizes the aquarium Suitable for freshwater and marine aquariums With Sera O2 plus, aquarists get a high-quality oxygen supply solution that ensures long-term stable water conditions and secures the well-being of aquarium inhabitants.
Content: 0.26 kilogram (€49.81 / 1 kilogram)

Average rating of 4.8 out of 5 stars
Sera pH-minus – Gentle pH Reduction for Optimal Water Conditions A stable pH value is essential for the health of fish and plants in the aquarium. Sera pH-minus offers an effective solution to lower the pH value specifically and permanently – ideal for species that prefer softer and slightly acidic water conditions. Advantages of Sera pH-minus: Gentle regulation: Lowers the pH value carefully without sudden fluctuations. Long-lasting effect: Keeps the pH value stable to ensure optimal living conditions. Versatile application: In addition to lowering pH, also ideal for removing lime residues from aquarium glass, pumps, and filters. By specifically adjusting the water values with Sera pH-minus, the well-being of sensitive fish and plant species is supported. Regular monitoring of the pH value ensures that the biological balance in the aquarium is maintained, minimizing stress and health risks for the aquarium inhabitants. For aquarists seeking a reliable method of pH adjustment, Sera pH-minus is the ideal choice.
Content: 0.1 Liters (€79.50 / 1 Liters)

Average rating of 4.8 out of 5 stars
Phosvec by Sera – Effective Phosphate Binding for Clear Aquarium Water Excessive phosphate levels in the aquarium can lead to algae problems and deteriorated water quality. Sera Phosvec offers a fast and reliable solution for binding phosphate to maintain the biological balance and ensure clear water. Advantages of Sera Phosvec: Immediate effect: Phosphate is bound directly after application, resulting in a quick improvement in water quality. Effective removal: The resulting white cloudiness from bound phosphate is removed via the aquarium filter or through a partial water change using the Sera gravel cleaner. Prevents algae growth: Reduces excess nutrients in the water to minimize unwanted algae growth. Regular use of Sera Phosvec supports stable water quality and provides optimal conditions for fish and plants. Especially for aquarists dealing with high phosphate levels, this product offers a reliable long-term control solution. With Sera Phosvec, your aquarium remains clear and healthy – ideal for a balanced and stable environment.
Content: 0.1 Liters (€59.50 / 1 Liters)

Average rating of 4.8 out of 5 stars
Sera Aquarium Filter Biostart Water Treatment – Effective Support for Biological Filtration Processes The Sera Aquarium Filter Biostart Water Treatment contains a specifically tailored mixture of cleaning bacteria and biologically active enzymes that promote the degradation of sludge and pollutants in the aquarium filter. This stabilizes the biological balance and improves water quality in the long term. Optimized Pollutant Reduction for a Healthy Aquarium Fish excretions, food leftovers, and decaying plants quickly accumulate as a sludge layer at the bottom of the aquarium and can impair water quality. The Sera Aquarium Filter Biostart Water Treatment supports the rapid breakdown of organic residues by increasing the activity of beneficial microorganisms in the filter. Perfect Combination with Other Water Care Products To achieve full effectiveness, the Sera Aquarium Filter Biostart Water Treatment can be combined with Sera Bio Nitrivec Aquarium Water Treatment. This combination ensures clear, pollutant-free aquarium water. Additionally, the use of high-performance filter media Sera Siporax Aquarium Filter Medium is recommended, as its high porosity provides an optimal colonization surface for microorganisms. Easy Application for Stable Water Quality The recommended dosage is 5 ml per 200 liters of aquarium water, applied directly to the filter sponge. The effect can be further enhanced by adding high-porosity filter material. With the Sera Aquarium Filter Biostart Water Treatment, aquarium enthusiasts get an effective solution for biological pollutant reduction, ensuring long-term stable water quality and healthy living conditions for fish and plants.
Content: 0.05 Liters (€159.00 / 1 Liters)

Average rating of 4.9 out of 5 stars
Sera Aquarium Mineral Salt Water Conditioner – Optimal Mineral Supply for a Healthy Aquarium The Sera Aquarium Mineral Salt Water Conditioner is the perfect solution for the targeted enrichment of osmosis and soft tap water with essential minerals. Thanks to its biologically necessary trace elements, it ensures balanced water quality that meets the individual needs of fish, plants, invertebrates, and microorganisms. Essential Minerals for a Stable Ecosystem The included minerals from natural waters provide the aquarium with calcium, magnesium, and potassium in their pure form. This promotes growth processes and prevents deficiency symptoms. KH-Neutral Formula – Perfect for Soft Water Tanks Thanks to the KH-neutral composition, the total hardness (GH) is only slightly increased, while the carbonate hardness (KH) remains unchanged. This makes the water conditioner ideal for discus aquariums and effectively protects against the feared hole-in-the-head disease. Versatile Benefits for Sustainable Care Improves reproductive ability and supports healthy offspring Strengthens the immune system and enhances disease resistance Optimizes scale development and promotes a strong skeleton Easy Application and Precise Dosage The recommended dosage is 5 g (approx. one level teaspoon) per 100 liters of water once a week. In cases of increased mineral demand, the amount can be adjusted individually. The standard dosage increases the GH by an average of 1.3 °dGH without affecting the KH. With Sera Aquarium Mineral Salt Water Conditioner, aquarium enthusiasts get a high-quality and effective solution for targeted mineral supply – for a stable, healthy, and species-appropriate aquarium.
Content: 0.105 kilogram (€85.24 / 1 kilogram)

Average rating of 4.8 out of 5 stars
Sera Aquarium Water Conditioner Toxivec – Immediate Aid for Clear and Healthy Water The Sera Aquarium Water Conditioner Toxivec is the ideal solution for quickly and effectively removing pollutants from aquarium water. It immediately eliminates chlorine, chloramines, ammonium, ammonia, and nitrite while preventing nitrate buildup, thus sustainably improving water quality. Effective Pollutant Neutralization for a Stable Biotope Thanks to its special formula, Toxivec binds heavy metals such as lead and copper and safely breaks down medication residues without affecting the biological balance. Especially after medication treatments, high stock density, or extensive cleaning procedures, it provides reliable first aid. Benefits of Sera Aquarium Water Conditioner Toxivec Immediately protects the fish stock Reduces algae growth by lowering pollutants Reduces the need for frequent water changes Application and Dosage for Optimal Results In cases of acute pollution, add 5 ml of Toxivec per 20 liters of water. For higher levels of contamination, the dosage can be increased up to five times and repeated as needed until water values stabilize. Note: Some soft-leaved aquarium plants may be sensitive to application. With Sera Aquarium Water Conditioner Toxivec, aquarium enthusiasts receive a reliable solution for rapid water purification – for a healthy and safe aquarium biotope.
Content: 0.1 Liters (€59.50 / 1 Liters)

Average rating of 4.8 out of 5 stars
Sera aquatan – Effective water treatment for healthy aquarium water Sera aquatan aquarium water treatment instantly transforms tap water into fish-friendly, mineral-rich water by removing harmful substances and adding essential minerals. It ensures optimal living conditions in freshwater and marine aquariums by binding chlorine, chloramines, and heavy metals while supplying valuable trace elements. Pollutant removal for fish-friendly water The product effectively eliminates: Chlorine and chloramines, which are toxic to fish and shrimp Heavy metals such as copper, zinc, and lead Ammonia, which can be deadly even in low concentrations These substances are reliably removed within a maximum of 10 minutes, protecting aquarium inhabitants from poisoning. Minerals for strong and healthy animals Sera aquatan also contains bioavailable minerals that promote the growth and resilience of fish and invertebrates: Calcium – for a strong skeleton and flawless scales Magnesium – supports muscle growth and vitality Manganese – promotes healthy development and fertility Iodine – strengthens the immune system and supports balanced development Application and dosage 5 ml per 20 liters of aquarium water during each water change, initial setup, or in stressful situations Multiple dosing possible if necessary Technical details Fast water treatment within 10 minutes Binds pollutants and supports biological balance Suitable for freshwater and marine aquariums With Sera aquatan aquarium water treatment, aquarists receive a high-quality water care solution that sustainably supports the well-being and health of their fish.
Content: 0.25 Liters (€15.80 / 1 Liters)

Average rating of 4.8 out of 5 stars
Sera Aquatan Blackwater Water Treatment – Natural Blackwater Effect for Tropical Aquariums The Sera Aquatan Blackwater Water Treatment creates an authentic blackwater effect as found in tropical regions and optimizes water quality for fish, shrimp, and crabs. Thanks to the innovative Bio-Protect Formula, it transforms ordinary tap water into dark, clear, fish-friendly freshwater that simulates the natural conditions of tropical waters. Benefits of Sera Aquatan Blackwater Water Treatment Promotes vitality and natural coloration of ornamental fish Creates biotope-appropriate water that positively influences the behavior of aquarium inhabitants Instantly binds heavy metals such as lead and copper, protecting sensitive organisms pH-neutral – it does not alter the pH value and remains stable Reduces algae growth by limiting the light intensity in the aquarium or pond Long-lasting coloration for a permanent blackwater appearance Highly concentrated – allows for an efficient and cost-saving application Application and Dosage for the Ideal Blackwater Effect Add 10 ml per 50 liters of aquarium or pond water After dosing, the water may temporarily become cloudy – this is part of the active process After a few hours, the water will clear and take on the typical dark and clear tropical appearance With Sera Aquatan Blackwater Water Treatment, aquarium enthusiasts create a nature-like blackwater environment that provides a healthy atmosphere and optimal living conditions. Perfect for tropical fish species and biotope aquariums.
Content: 0.1 Liters (€69.50 / 1 Liters)

Average rating of 4.8 out of 5 stars
Sera Bio Nitrivec Aquarium Water Treatment – Biological Pollutant Control for Clear Water The Sera Bio Nitrivec Aquarium Water Treatment is a highly effective liquid filter medium that ensures effective reduction of ammonium and nitrite through millions of cleaning bacteria. By providing optimal colonization surfaces for bacteria, it supports the biological stability of the aquarium and ensures long-term healthy water. Natural Pollutant Degradation Mechanisms for a Stable Ecosystem Through degradation and excretion processes, toxins such as ammonium and nitrite can accumulate in the aquarium water. The Sera Bio Nitrivec Water Treatment helps quickly and continuously break down these harmful substances, ensuring stable water parameters and maintaining the biological balance. Mineral Volcanic Rock for Water Optimization Additionally, the product contains high-quality volcanic rock, which serves several important functions: Effective pollutant binding to prevent water cloudiness Excellent colonization surface for cleaning bacteria Contains essential minerals such as calcium, potassium, and magnesium, which are indispensable for the health of fish and plants Combination with Other Water Care Products for Optimal Effect In combination with Sera Aquatan Aquarium Water Treatment, a new fish stock can be added to the aquarium after just 24 hours. Additionally, the effect can be further enhanced by using high-performance filter media Sera Siporax. Advanced Formula for Maximum Efficiency The Sera Bio Nitrivec Aquarium Water Treatment is the optimized development of the classic Sera Nitrivec, with improved bacterial culture and more efficient pollutant reduction. With Sera Bio Nitrivec Aquarium Water Treatment, aquarium enthusiasts receive a powerful, biological filter medium that ensures crystal-clear, healthy, and biologically active water – perfect for freshwater and marine aquariums.
Content: 0.05 Liters (€99.00 / 1 Liters)


























































































































































