Here's some suggestions for saltwater plants that don't require any special lighting or other equipment:
Shaving Brush
Shaving Brush Plant, Penicillus capitus, grow in sandy substrates via rhizoidal "root balls" or holdfasts. Its elongated stalk and green grass-like upward branches make a nice contrast against other natural decorations and corals in the home aquarium. Like the Halimeda Plant and like Coralline Algae, the Shaving Brush incorporates a hard Calcium Carbonate skeleton within its living tissue. This Caribbean-Atlantic native is functional in that it helps in the removal of organic nutrients because it consumes many waste by-products in the home aquarium. This easy-care marine plant does well in a variety of conditions. Medium light and water-levels should suit it fine. Calcium and iron will definitely be beneficial in overall health and in growth.
Turtle Weed: Rock
Turtle Weed, Chlorodesmis fastigiata, adds attractive grassy thatches that bring richness to the terrain of the home aquarium. Also known as Maiden’s Hair or Turtle Grass, this marine fauna does contain a mild toxin that helps deter it from being nibbled upon by fish and invertebrates. This toxin does not seem to affect members of the Tang family, who enjoy grazing from and eating the fine-filamented branches that form the majority of the plant. Turtle Weed is beneficial to the home aquarium in that it help to consume nitrates. It also uses carbon dioxide, converting it to oxygen much like its non-marine plant cousins. Intentional placement of macro algae in the home aquarium can be a help in fighting the typically nuisance algae forms by consuming the nutrients from which the nuisance algae would feed
Grape Plant: Green
Green Grape on Rock, Caulerpa racemosa w/scleractinia, is a decorative and beneficial marine plant. Known as Sea Grapes or, to the Japanese, sennarizuta, Green Grape is helpful in the removal of organic nutrients because it helps to consume many waste by-products in the home aquarium. In the proper conditions, most any Caulerpa will grow very rapidly. For this reason, frequent pruning is necessary. Because Caulerpa has been shown to be a nuisance in many seaside environments, it is important to freeze any clippings then place them in the trash. Do not return clippings to any aquatic marine environment. This is actually illegal in many areas. Removing the pruned portions removes the waste nutrients from the aquarium. If growing Caulerpa in a sump, it is advised to leave a light on constantly. This prevents the Caulerpa from “going asexual” (which begins Caulerpa reproduction) and releasing reproductive toxins into the aquarium. These toxins can reduce oxygen levels in the aquarium to dangerous levels. In the wild, Caulerpa grows on rocky ledges and in murky, sandy conditions. With routine pruning and regular additions of calcium and iron, Grape Caulerpa can be a benefit to the home mini-reef environment.
