Problems Caused by Plastic Aquarium Plants

Low Oxygen Levels

• High dissolved oxygen levels are the essence of a healthy aquarium. All species of fish thrive in an oxygen-rich environment, while parasites, algae, snails, and other aquarium nuisances prefer hypoxic environments. An aquarium with low oxygen levels is a fast ticket to a vicious cycle of algae overgrowth, infestation, and mass die-off of aquarium fish.
  Through respiration, live plants decrease the mount of carbon dioxide in the water and increase levels of oxygen. Since artificial plants to not engage in any form of respiration or photosynthesis, they do nothing to prevent hypoxia-related complications from arising within the aquarium ecosystem.

Toxin Buildup

• Even a very well-filtered aquarium is prone to a buildup of toxins, which can make fish sick and encourage the growth of parasites and algae. Live plants help to absorb and eliminate toxins, including nitrates, ammonia and carbon dioxide. Artificial plants not only fail to absorb these poisons, but they also can contribute to toxin buildup due to the pigments and petrochemicals used in their production.
  The introduction of toxins through plastic plants can be avoided. Tight-celled, high quality artificial plants are less likely to contain outgassing chemicals or dyes that can leach into the surrounding water. Still, even the natural waste products of aquarium fish will eventually build up to intolerable levels in an aquarium with only plastic plants, unless the tank is exceptionally well-filtered.

Infestation

• Many aquarists are concerned about the fact that live plants sometimes carry the eggs of parasites with them. While this is a legitimate concern, this problem is usually mitigated by the detoxifying effects of live aquarium plants. Since plastic plants lead to poor water quality, they create a perfect environment for parasites and other unwanted aquarium guests.
  Since artificial plants do not compete with algae, unwanted "scum" often appears in aquariums with only plastic plants. Without treatment, this problem can escalate, eventually leading to a severely compromised aquatic ecosystem. Snails also appear frequently in the hypoxic environments created by plastic plants, and fish parasites like ich, fin rot, and flukes become much more prevalent.

Inadequate Nutrition

• Few tropical fish formulas provide complete nutrition for all species of omnivorous fish. In a well-populated community aquarium, it can be difficult to ensure that every individual is eating a balanced diet, even if the aquarium's staple food source is supplemented. Omnivorous fish that do not eat a balanced diet are prone to weakness, disease and premature death.
  Although live plants can provide a valuable food source to herbivorous and omnivorous aquarium fish, plastic plants do not offer this advantage. As a result, fish in aquariums with only artificial decorations are more likely to suffer from malnutrition.This long-term complication can drastically reduce the life-span of an aquarium.

Aesthetic Problems

• While plastic plants can be very beautiful (and convincing) they are not usually considered to be as attractive as live aquarium plants. Cheaper plastic plants often look "fake" or tacky, and artificial plants cannot sprawl or grow to naturally populate an aquarium. An aquarium full of plastic plants will often look scraggly and synthetic.
  To some aquarists, plastic plants also present a philosophical drawback. Aquascaping, or the design and maintenance of a healthy aquatic ecosystem, is considered to be a core component of fishkeeping. Depending on the outlook of the aquarist, plastic plants might seem as nonsensical as the concept of plastic fish.