When talking about plants suitable for the front of the tank, most of the aquascaping “community” automatically think of Glossostigma elatinoides, Echinodorus tenellus, Lilaeopsis, etc. However, several species of cryptocoryne provide alternatives to make the front scenery of an aquarium look impressive, or they can form a suitable enrichment to an otherwise perhaps monotonous low stand. What I personally find most fascinating about these plants is their diversity and difference. As long as they dominate the aquarium, they create a mysterious atmosphere of an ancient world. If they are subtly (but sometimes randomly) planted only “here and there” and the eye of the observer notices them only on a second, maybe third glance, they can provide a nice spice and diversify the overall layout.
Overall, cryptocorynes are said to be less demanding plants. However, I have a feeling that this is only because the aquarists in question have not encountered more sensitive species, or less demanding is certainly only understood in terms of less demanding lighting intensity. But nice colouration, compact and dense growth can only be achieved by strong lighting and proper fertilization.
Cryptocorynes can prove to be quite demanding plants – with sudden changes, experiments with fertilization and “accidents” in the aquarium, they sometimes completely disintegrate within a short time. They grow relatively to very slowly (depending on the species and conditions), and older leaves may be infested with algae. Really nice specimens are only found in aquariums where stable and good conditions prevail for a long time.
Among suitable candidates for the front zones of the aquarium, I will mention three taxa.
I will start with Cryptocoryne wendtii. Several colour and growth variants of this species are cultivated. Some can grow to a height of about 25 cm, which rather qualifies them for use in the middle zone of the aquarium. I grow the ‘Tropica’ variant. For me it thrives amongst dense growth of E. tenellus. Its dark brown-red colouring and wavy leaves contrast well with the ubiquitous green. It grows to a height of about 5-10 cm. It can be kept at bay, so to speak, by trimming back old and large leaves. With the help of the whippers, it twists in different directions and sometimes ‘peeks out’ on its own in unplanned places. It grows (for a cryptocoryne) moderately fast.
The smallest representative of the cryptocoryne is Cryptocoryne parva. It grows to a height of 5-10 cm. It has oblong leaves of light green colour. It is literally an art to use this plant exclusively to furnish the front of the aquarium. The main reason for this is its extremely slow growth. If you think, for example, that Anubias or ferns grow slowly, they are sprinters compared to this cryptocoryne. I personally do not know of a slower growing plant.
If we decide to create a carpet planting using only Cryptocoryne parva, we need to plan the appropriate number of specimens, plant them a few inches apart, and make sure that they are not overwhelmed by faster growing plants and get enough light. I personally owned one mini aquarium where I planted this plant exclusively. At the moment I am growing it amongst a stand of E. tenellus just as a diversion.
Beware of confusion with Cryptocoryne x willisii (lucens), especially if you plant both species in the same tank. Young plants have similar colouring and leaf form. However, this Cryptocoryne grows to a larger size and is more suitable for grouping in the middle zones of the aquarium.
The aforementioned Cryptocoryne x willisii (lucens) is similar in leaf form and colouration to the previous species, but grows to two to three times the height. Its oblong leaves of a deep green colour are a shade darker than the previous species, firm, with a very fine texture. Cryptocorynes can disintegrate with rapid environmental changes, aquarium disasters, etc. It is customary to speak of “cryptocoryne disease” even though it is not a de facto disease, which would be a chapter in itself… This is where this species proves to be quite resilient – while there is hardly anything left of other cryptocorns in the aquarium, these can last the longest – but of course they can’t withstand everything.
These plants are not suitable for filling larger areas in the aquarium. It will perform best if planted in the middle parts of the tank, even in large clumps – i.e. several plants together. Over time, it will form a sort of ‘clump’ and the observer will not realise this when walking around the aquarium.
Let us try to create a contrast with the surrounding plant or vegetation with this group. The colour and shape of the leaves will predestine it to do this. This will create a kind of stable point where we can unconsciously stay for a while while observing the aquarium. We will take advantage of the characteristic of C. x willisii that it grows very slowly and its appearance will not change too quickly.
If the other surrounding plants are faster-growing species, we will of course have to take care to free C. x willisii at certain intervals and give it direct light. However, longer breaks in partial shade will do it no harm. Of course, it will perform and grow most beautifully with strong good quality light and good conditions. This is when it starts to multiply gratefully with its typical whip-like shoots, which can be quite strong and thick. It will also surprise you with its vigorous root structure, which we are kneelingly aware of if we want to transplant/remove the plant and in doing so we will willy-nilly “aerate” the bottom, rearrange the layout of the aquarium and shock the more sensitive aquarium inhabitants. This is not to show the plant in a bad light, it is simply something to keep in mind. It’s proof that this plant (like all cryptocorals, by the way) gets most of its nutrients from the bottom. This breaks down excess nutrients in the substrate and has a positive effect on the “microclimate” in the aquarium.
A moderately experienced aquarist will have no serious problems with it. If there are faster growing plants in the aquarium, the correct dosage of fertiliser needs to be mastered over time – too little means that most of the nutrients will be consumed by the “sprinters” and the cryptocoryne will not show its full glory. Too much fertiliser, especially in ‘slower’ tanks with mosses, ferns and other cryptocorynes, can cause the older leaves to droop and, in extreme cases, the cryptocoryne to decay. Once conditions have stabilised, the growth tends to regenerate after a few weeks.