Single Components for Specific Use

Recognizing deficiencies takes a bit of practise. Most aquascapers develop an eye for what's low or what is present in overabundance. Some enthusiasts have dispensed with chemical tests altogether (not recommended for beginners).

Standard single-component fertilisers are not suited to take action against specific deficiencies because they add a range of nutrients to the water indiscriminately. This is where Aqua Rebell comes in with individual components and specific mixtures.

Nitrogen (N)

Nitrogen is the most important macro-element. Nitrogen deficiency has a number of symptoms: The colour of the aquatic plant fades to a yellowish green, the older leaves being more yellow than the younger ones. However, older leaves will not die off.

A strong nitrogen deficiency may show in one or several ways. Smaller, lighter coloured leaves may also point to a lack of nitrogen. Died-off shoots (partially dark-coloured and/or with curly growth) or very slow growth might also be a symptom of nitrogen deficiency.
In some aquatic plant species, the leaves may also show a reddish discoloration.

Nitrogen can be added using the following products:

Phosphorus (P)

Phosphorus is taken up as a phosphate compound and is an essential macro-nutrient. In the absence of phosphorous the aquatic plant stops growing altogether and turns a lighter colour in some parts. Certain plants may turn darker. Older leaves may show a spot algae infestation and fall off more easily. Occasionally, brown spots on the leaves may appear. Some plant species may turn an intense purple, as the pigment anthocyanin accumulates. The deficiency symptoms look very similar to those of nitrate.

Phosphorus can be added using the following products:

Potassium (K)

Potassium is one of the core-nutrients for plants, besides nitrogen and phosphorus. It is absorbed by aquatic plants as a potassium-cation (K+). Deficiency symptoms are varied: Smaller necroses form on the older leaves. At the beginning, they are only visible as small black dots, however, they often get progressively larger and may have a yellowish rim in some parts. New leaves are reduced in size and surface. In other plant species, the older leaves may turn yellow before they die off, however, in contrast to a magnesium deficiency, the leaf veins turn yellow, too.

Potassium can be added using the following products:

Iron (Fe)

The first fertilisers especially designed for aquarium plants that were available in the trade were iron fertilisers, which demonstrates the importance of iron and the frequency of iron deficiencies in water plants. Of all micro-nutrients, iron is used in the largest quantities. Some authors even count it as a macro-nutrient. In the case of an iron deficiency, less chlorophyll forms in the new leaves of aquatic plants. The leaves and stems are more or less of the same colour. The shoot tips of Ceratophyllum (Hornwort) e.g. first attain a reddish purple stain and then turn white.
The shoots of Egeria densa (Waterweed) first turn a yellowish green to yellow, and its leaves grow smaller. Moreover, the leaves grow very close to the stem.
New growth in Echinodorus species remains smaller in the case of a slight deficiency, and develops lighter-coloured spots or wide longitudinal lighter-coloured stripes.
When the deficiency is more pronounced, the plants tend to have no chlorophyll at all in their new leaves, which die off soon for the same reason. The leaf tissue turns white faster than the leaf veins, which remain greenish. A strong iron deficiency results in necrosis (black spots and holes) in the new leaves, which will remain significantly smaller.
Fast-growing plants are the first to show an iron deficiency.

Iron can be added using the following products:

Magnesium (Mg)

Magnesium is dissolved in water as a cation (Mg2+) and is absorbed by the plants in this form. Magnesium deficiency often has the same symptoms as iron deficiency, as a lack of magnesium blocks the absorption of iron. Heavy chlorosis may occur. The leaves turn yellow to white and may also have purple discolourations at their tips, with some degree of curly growth possibly. These deficiency symptoms may also occur on young leaves or shoot tips.

Magnesium can be added using the following products:

Calcium (Ca), Boron (B) and Miscellaneous Trace Elements

In the case of a calcium deficiency, new growth on plants is small and stunted, and leaf tissue is reduced. However, the leaf nerves remain their original size. Leaves may be curly and do not grow straight. New growth may be a very light colour, even white. All in all, though, please keep in mind that there is almost always enough calcium in tap water and that calcium deficiency is very rare. Boron deficiency looks very similar to calcium deficiency but is also rare as boron is added by almost all iron fertilisers and thus ought to be present in sufficient quantities at almost any time. We will not go into detail on other trace element deficiency symptoms, as a lack of them is almost impossible and should be averted by the use of any complete iron fertiliser. A lack of N (nitrogen), P (phosphorus), K (potassium) as well as iron and magnesium is always more probable and should thus be considered first.

Trace elements can be added using the following products: