A planted aquarium runs more stably than a bare tank because plants consume the same nitrate and phosphate that feed algae. Plants also oxygenate the water during daylight, buffer pH swings, and give shy fish cover. The persistent myth that planted tanks require pressurized CO2 keeps many new aquarists away from plants for years, when in fact the twelve species in this guide grow well under basic LED lighting with no injected carbon. Pick six to eight from this list, plan placement by growth height, and a 20 gallon tank fills in 6 to 10 weeks.
How to choose plants for a starter tank
Three traits determine whether a plant thrives in a low tech setup: light demand, growth speed, and nutrient feeding mode. Low light plants tolerate 20 to 30 PAR and grow steadily without supplementation. Fast growers outcompete algae for nutrients. Root feeders need substrate fertilization (root tabs), while water column feeders take in nutrients through their leaves and respond to weekly liquid fertilizer dosing.
Aim for a mix: two or three fast growing background plants, two or three midground species, and one or two foreground or carpet plants. Add a floating species for nutrient export and shade. This mix covers 70 percent of the planting strategy that experienced aquascapers use.
The 12 starter species
1. Java Fern (Microsorum pteropus). Light: low. Growth: slow. Placement: midground attached to rock or driftwood. Java fern roots are rhizomes that must not be buried, attach the plant to hardscape with thread or super glue gel. It tolerates pH 6.0 to 8.0 and temperatures 65 to 82 degrees. Goldfish ignore it. New leaves emerge from the rhizome, old leaves yellow and should be trimmed. A single Java fern doubles in size every 4 to 6 months under low light.
2. Anubias Nana (Anubias barteri var. nana). Light: very low to medium. Growth: very slow. Placement: foreground or midground attached to hardscape. Like Java fern, the rhizome must not be buried. Anubias thrives in shaded areas and is the most forgiving aquarium plant sold. It grows new leaves every 4 to 8 weeks. A single Anubias plant lives 5 to 10 years.
3. Amazon Sword (Echinodorus bleheri). Light: medium. Growth: medium. Placement: background. A rosette plant that grows to 18 inches tall and 12 inches wide in a 20 gallon tank. It is a heavy root feeder and requires root tabs (Seachem Flourish Tabs or Osmocote+) every 3 to 4 months. Amazon swords are dramatic centerpieces that fill the back of a tank in 8 weeks.
4. Cryptocoryne wendtii. Light: low to medium. Growth: slow to medium. Placement: midground. Available in green, bronze, and red varieties. Crypts drop all their leaves when first planted (a stress response called “crypt melt”), then regrow within 4 to 6 weeks. The new growth is permanent and forms a 6 to 8 inch tall bush.
5. Vallisneria spiralis. Light: medium. Growth: fast. Placement: background. Tall grass-like leaves reach 18 to 24 inches and spread by runners. A single plant creates a forest of vallisneria across the back of a 20 gallon tank in 8 to 10 weeks. It needs harder water (KH 4+) and dislikes liquid carbon (Excel melts it).
6. Hornwort (Ceratophyllum demersum). Light: low to high. Growth: very fast. Placement: floating or anchored. Hornwort has no real roots and floats unless weighted. It grows 2 to 4 inches per week under decent light and is the strongest nutrient consumer of the twelve species. Use it during cycling, during algae outbreaks, or as permanent background mass.
7. Water Sprite (Ceratopteris thalictroides). Light: medium. Growth: fast. Placement: floating or background. Lacy leaves that float or root. Like hornwort, water sprite consumes nutrients aggressively and gives baby fish dense hiding cover. Pinch off side shoots and replant for free propagation.
8. Java Moss (Taxiphyllum barbieri). Light: low to medium. Growth: medium. Placement: attached to anything. The most forgiving moss. Java moss attaches to rocks, driftwood, and tank walls. It hosts shrimp colonies and gives fry safe cover. Trim with scissors when it gets shaggy.
9. Dwarf Sagittaria (Sagittaria subulata). Light: medium. Growth: medium. Placement: foreground to midground. Grass-like plant that reaches 4 to 8 inches and spreads by runners. A practical carpeting plant for low tech tanks because it does not require CO2. A dozen plants cover a 24 inch tank base in 10 to 12 weeks.
10. Bacopa caroliniana. Light: medium. Growth: medium. Placement: background. Stem plant with round green leaves. Top the plant when it reaches the surface, replant cuttings, and the original keeps growing. Easy to propagate to fill a 20 gallon tank from a single bunched starter.
11. Marimo Moss Ball (Aegagropila linnaei). Light: low. Growth: very slow. Placement: anywhere. A spherical green algae that grows naturally and lives 30+ years in good conditions. Rotate it once a week to prevent dead spots. Marimo balls suit nano tanks and shrimp tanks where they double as climbing structures.
12. Frogbit (Limnobium laevigatum). Light: medium. Growth: fast. Placement: floating. Round green floating leaves with feathery roots. Frogbit blocks excessive light, shades shy fish, and pulls nutrients. Trim the colony back monthly because it covers the surface fast.
A practical 20 gallon planting plan
For a 20 gallon long tank (30 by 12 inches), the following layout fills in 8 to 10 weeks:
- Background left: 4 hornwort stems or 1 amazon sword
- Background right: 6 vallisneria runners or 6 bacopa stems
- Midground center: 1 piece of driftwood with 3 anubias nana attached
- Midground right: 2 cryptocoryne wendtii bunches
- Foreground: 12 dwarf sagittaria plugs spaced 1 inch apart
- Surface: 6 frogbit plants
- Hardscape: 1 piece of spider wood with java fern and java moss attached
Total plant cost runs 60 to 90 dollars at retail. The tank looks sparse for the first 2 weeks, fills out at week 6, and becomes a jungle by week 12.
Fertilizer and lighting schedule
Low tech plants need minimal supplementation, but a small weekly dose closes the nutrient gap.
- Liquid all in one: Thrive Light or Aquarium Co-Op Easy Green, dosed once weekly at 1 pump per 10 gallons
- Root tabs: under heavy root feeders (swords, vallisneria) every 3 to 4 months
- Lighting: 6 to 8 hours per day on a timer
- No CO2 needed, but Seachem Excel at 1 ml per 10 gallons daily helps battle algae
See our low tech vs high tech planted tank guide for the trade off math, and aquarium water parameters explained for the parameters plants prefer. The /methodology page covers our testing protocol.
Frequently asked questions
Do I really not need CO2 for these plants?+
Correct. All twelve species in this guide grow steadily under 30 to 50 PAR lighting with liquid carbon supplementation (Seachem Excel) or no carbon at all. CO2 injection accelerates growth two to three times over, but it is not required for plant survival. The trade off is slower growth, which actually benefits new aquarists who do not want weekly trimming.
How much light do low tech plants need?+
Low tech plants thrive at 30 to 50 PAR at the substrate, which translates to a basic LED fixture rated 25 to 40 watts on a 20 gallon tank. The Fluval Plant 3.0, Nicrew SkyLED Plus, and Twinstar S series all hit that range. Run lights 6 to 8 hours per day. Longer photoperiods favor algae before they favor plants in a low CO2 environment.
Which plant grows fastest for nutrient export?+
Hornwort and water sprite are the speed champions. Both float or root and pull ammonia, nitrate, and phosphate aggressively. A clump of hornwort the size of a fist removes the nitrate output of three small fish per week in a 20 gallon tank. Use either species during cycling or to control algae outbreaks.
Will my goldfish or cichlids eat aquarium plants?+
Goldfish, oscars, large gouramis, and many cichlids destroy soft leaved plants. The plant resistant species are Anubias (tough leaves), Java fern (bitter taste), and Cryptocoryne species (avoided by most herbivores). Hornwort survives some grazing because it grows faster than fish eat it.
Do I need substrate or can I use plain gravel?+
All twelve species in this guide grow in plain inert gravel or sand because they are root and water column feeders. A rich plant substrate like Fluval Stratum or ADA Amazonia speeds growth but is not required. The exception is carpeting plants which need a fine substrate to anchor.
Related product reviews
Fluval Plant 3.0 LED Review (2026)
Tetra Aquarium 10 Gallon Complete Tropical Fish Kit Review (2026)
Fluval Flex 9 Gallon Glass Aquarium Kit Review (2026)
Morgan Davis
Morgan Davis writes for The Tested Hub.