¿Cuándo puede no funcionar la APT?

En acuarios nuevos

Es normal que los acuarios de menos de 6 meses tengan diversos problemas de algas, la mayoría de los cuales pueden evitarse con un ciclado adecuado antes de la siembra. APT no puede compensar un ciclado inadecuado.

También es normal que las plantas tarden varias semanas en adaptarse. El APT ayuda a acelerar el proceso, pero aún así hay que tener paciencia. En tanques sin CO2, esto lleva de 2 a 3 meses. La adaptación puede implicar la caída de hojas (¡sí!) y/o la aparición de hojas deformadas. La respuesta más difícil, aunque la más eficaz, es jugar menos y proporcionar un entorno estable en el acuario para que las plantas se adapten. Busque mejoras en las HOJAS NUEVAS, no en las viejas.

En acuarios maduros

A mature tank can respond to better nutrition in several ways. The best (and most common) outcome is healthier NEW GROWTH. Old leaves do not rejuvenate even when conditions improve, and may even deteriorate faster, as we explain here.

In rare cases, better nutrition can seemingly trigger algae. This can happen:

(a) if there is prior accumulation of organic waste, especially on mosses and slow growers. When plants adjust to a new nutritional environment, they release proteins that serve as food for algae. The combination of accumulated organic waste + excreted proteins can be a trigger for algae.

(b) if volatile organic matter is released due to replanting or cleaning. In mature tanks, volatile organic matter builds up naturally in the substrate and hard-to-reach corners. When inadvertently released, often coincidentally with improved nutrition, algae can bloom. This can be avoided by performing thorough water change the 2Hr way after replanting / revamping the tank.

(c) if seemingly ‘OK’ plants (especially slow growers like Mosses, Bucephalandra, Crypts, Java Fern, Anubias, Alternanthera species etc.) are actually not as healthy as they appear. Plants often respond to improved tank conditions (better nutrition, or lighting, or CO2…) by accelerating the shedding of older, less healthy leaves. This attracts algae, which help in the decomposition process. Slow growers that are not healthy are especially hard to spot, as they can be in 'Zombie’ states for a long time, as we describe here.

(d) finally, if you are making a drastic change in dosing regime (e.g. very lean to something alot richer, or vice versa), this forces plants to reprogram their cells to adapt and this process almost certainly triggers algae. A gradual transition over 2-3 weeks often helps. But the longer slow-growers have adapted to a particular environment, the harder it is for them to 'switch'. 

If you have a mature tank (> 1 year old) and are looking to improve plant health / growth, please check out this article.