Dennerle Plant Care NPK 250ml

Macro nutrient fertilizer for aquariums with no or low fish population

The three macronutrients N = nitrogen (nitrate), P = phosphorus (phosphate) and K = potassium are of particular importance. The addition of N and P is usually not necessary in normal, planted community aquariums, as these substances enter the aquarium in sufficient or sometimes even too large quantities via the food and fish excretions. In the case of sophisticated plant aquariums or aquascaping aquariums, on the other hand, the situation is different. They have an above-average nutrient requirement, especially when it comes to macronutrients. With these aquarium types, an N or P deficiency can quickly occur, especially with no or low fish stock. A K deficiency is also possible, but less common, as potassium is always present in tap water in a certain amount and is regularly introduced via complete iron fertilisers such as Plant Care Pro. For demanding plant aquariums, it is therefore very useful to keep an eye on the macronutrients and supplement them if necessary. Particularly important with an NPK fertilizer is the biological balance of nutrients. The nutrient ratios in Plant Care NPK were chosen in such a way that all three macronutrients are absorbed by the plants in equal proportions. This means that even with longer-term, regular use, there can be no deficits or detrimental accumulations of individual nutrients. This is because nutrient imbalances must always be avoided, as they usually lead to algae problems.

When do I use Plant Care NPK?

Each aquarium has a specific nutrient consumption depending on the amount of plants, plant species, animal population, feeding, water change and growing conditions (amount of light/lighting time, CO₂-Addition, filter technology, etc.). The required NPK addition should therefore be determined individually for each aquarium. Plant Care NPK is only used when necessary, i.e. when there is a real deficiency of macronutrients. We recommend measuring the nitrate and/or phosphate content weekly and dosing Plant Care NPK accordingly. You can also measure the potassium content of the aquarium water (tests in specialist shops). However, this measurement is usually not necessary, as the tap water plus Plant Care Pro and Plant Care NPK supplies sufficient potassium. An overdose of potassium is hardly possible in practice and is usually not disadvantageous. Significant overdoses of nitrate and phosphate, on the other hand, can promote algae growth. Plant Care NPK should therefore not be used at the beginning without first measuring the nitrate and ideally also the phosphate content. If the tap water used for the water change does not contain exceptionally high amounts of nitrate or phosphate, the measurement of the nitrate content alone will later be sufficient as a basis for deciding on NPK fertilisation and dosage. Simple immersion tests can also be used for this purpose, e.g. the Dennerle WaterTest 6in1.

Dosage & Application

If you have measured and fertilized regularly for several weeks, you can see at what level the measured values settle and what macronutrient additions the aquarium needs. Then you can add the determined weekly dose of Plant Care NPK as standard and increase the measurement intervals to 2 to 4 weeks with a clear conscience. A good guideline is 10 ml / 100 L / week, which corresponds to an addition of 5 mg/L nitrate, 0.4 mg/L phosphate and 2.5 mg/L potassium. If the tap water used for water change contains exceptionally high levels of nitrate (e.g. 50 mg/L) but hardly any phosphate or high levels of phosphate (> 1 mg/L) but hardly any nitrate, then the use of Plant Care NPK is not recommended in order to avoid adversely high levels of individual macronutrients and nutrient imbalances. In this case, Dennerle Plant Care N or Plant Care P single nutrient fertilisers should be used to compensate for nutrient gaps in a targeted manner. Because in addition to the absolute nutrient concentration, the nutrient ratios are also important. The nitrate-phosphate ratio should ideally be in the range of 10:1 to 15:1. If the tap water contains only small amounts of potassium (e.g. < 3 mg/L), Dennerle Plant Care K should be used. This is often the case with very soft water. You can find out the analysis values of your own tap water from the local water supplier. They can be easily accessed via the Internet. In addition, potassium is one of the few nutrients that only enter the aquarium in trace amounts through fish food. A macro nutrient fertiliser must always be used in combination with a micro nutrient fertiliser. For a complete supply of nutrients and the best possible plant growth, we recommend combining Plant Care NPK with Plant Care Pro.

Macro-nutrients, guideline values for plant aquariums