Planted Tank Gear Planted aquarium gear
Menu
Calculator Filters Heaters Lights Compare Guides
Long-form guide

Starting a Planted Tank: the complete equipment checklist

Everything you need to set up a planted freshwater aquarium: tank, filter, heater, light, substrate, CO2, test kits, with explanations for each choice.

Updated April 16, 2026

The short version

A planted tank needs, in priority order: a tank (start with 20 gallons if you can; nano is harder), a light matched to your plant choices, substrate that either stores nutrients or that you can dose around, a filter that moves water without shredding plants, a heater sized to your room, and a test kit to know what’s happening. Everything else is situational. CO2, timers, ferts, pre-filters: those can wait until you understand what your tank wants.

Use this as the planning pass before buying anything. It’s long because the decisions compound. The wrong tank size makes everything else harder. The wrong substrate wastes money. The wrong light feeds algae instead of plants. Spending 30 minutes here saves months of remediation later.

Tank size: the decision that determines everything else

Twenty gallons is a forgiving size. Big enough to buffer parameter swings, small enough to fit most apartments, cheap enough to replace if you crack it. A 20 gallon can tolerate a surprising range of mistakes (an overdose of fertilizer, a missed water change, a sudden cold night) without the consequences landing hard on your livestock.

A ten gallon works, but beginners often underestimate how quickly nitrate climbs in a small tank, and how fast temperature swings happen. Anything under five gallons is advanced mode. Experienced keepers make them look effortless; first-timers routinely fail at them. Skip nano as your first tank.

Tall vs long: long wins for planted tanks. A 20 gallon long (30”×12”×12”) has 30% more surface area than a 20 gallon tall (24”×12”×16”) of the same volume. More surface area means:

If you have the shelf space, go long.

Dimensions matter for lighting. A tall tank with 24 inches of water column requires a stronger light to reach the substrate than a long tank with 12 inches of depth. Factor this in when choosing lights.

Light: what actually drives plant growth

Light drives everything in a planted tank. Too little and plants limp along, turn yellow, and eventually rot. Too much without matching CO₂ and nutrients and you grow algae instead of plants. Matching light intensity to your plant choices and setup complexity is the single most common beginner miss.

Low-tech plants (Java fern, Anubias, Cryptocoryne, Vallisneria, Amazon sword, mosses): A budget LED like a Hygger 957 is sufficient. Run it 6–8 hours per day. These plants tolerate a wide light range and don’t require CO₂. They’re the “set it and forget it” group, perfect for first tanks.

Medium-tech (stem plants, swords, carpets without CO₂): A Fluval Plant 3.0 or equivalent. Dimmable is worth paying for, since you’ll often want to start lower and ramp up. Some plants in this tier work without CO₂ (dwarf hairgrass, crypts) but grow faster with liquid carbon supplementation.

High-tech (red plants, demanding carpets, CO₂ injection): A Week Aqua P600 Pro or ADA-class light. These systems fight back if you under-light. They also fight back if you over-light, so matching lights to CO₂ injection rate is crucial. See Best light for a 20 gallon planted tank guide for the detailed tier breakdown.

Substrate: active or inert

Two schools of thought, both work:

Active substrate (Fluval Stratum, ADA Aqua Soil, UNS Controsoil) releases nutrients over time, buffers pH downward into the 6.0–6.8 range, and softens water. Growth is faster; shrimp like it. Granules break down over 2–3 years and must be replaced. Good for: soft-water fish, Caridina shrimp, carpeting species, faster establishment.

Inert substrate (CaribSea Eco-Complete, Seachem Flourite, plain sand, gravel) doesn’t break down and doesn’t swing pH. You dose fertilizers to feed plants and use root tabs for heavy root feeders. More stable long-term; less convenient week-to-week. Good for: hard-water fish, livebearers, larger tanks, keepers who prefer dosing over substrate maintenance.

Pick active for shrimp-forward tanks and fast establishment. Pick inert for simplicity, stability, and fish that prefer harder water. See Best substrate for a planted tank for the detailed comparison.

Depth: 1.5–2.5 inches is the planted-tank standard. Slope from front (shallow) to back (deep) for visual depth. Carpet species prefer the shallower end; tall rooted plants prefer the deeper end.

Filter: don’t overthink this

For a planted tank, filter flow should turn over the water 4–6× per hour in real flow (not rated flow). Rated flow is measured without media. Actual flow is typically 40–60% of rated. A 20 gallon tank wants a filter rated for 150–250 GPH to deliver 100–150 GPH actual.

Canisters (Fluval, Oase, Eheim): quieter, more media capacity, hide in the cabinet. Cost 3× an HOB. Good for aesthetics-focused keepers.

HOBs (AquaClear, Aqueon): cheaper, simpler, easier to maintain. Visible on the back of the tank. Good for budget builds and most casual keepers.

Sponge filters: cheapest, safest for shrimp and fry, lowest maintenance. Visible in-tank. Good for dedicated shrimp or breeding tanks.

For most first-time planted tank keepers, an HOB like the AquaClear 50 is the right pick. See filter guides for the detailed comparison by tank size and livestock.

Heater: the quiet killer when chosen badly

Size the heater to tank volume AND room temperature. A 50-watt heater is fine for a 10 gallon in a 70°F room; the same tank in a 60°F basement needs more. Rule of thumb:

For a 20 gallon, 100 watts is the standard pick.

Reliability matters more than features. A cheap heater that fails stuck-on cooks the tank. A reputable heater that fails cold gives you days to notice. The Eheim Jager has been the reliability standard for decades for this reason.

Dual heaters are better than single on any tank you care about. Two 50-watt heaters both set to 77°F give you redundancy. If one fails cold, the other holds. If one fails stuck-on, the other’s thermostat still shuts off at 77°F.

Preset “plug and play” heaters fail eventually and always at the wrong time. See Best heater for a 20 gallon planted tank for details.

CO₂ (only for high-tech)

Injected CO₂ is the dividing line between “my plants grow” and “my plants explode.” If you want carpeting plants, red plants, or heavy pruning weekends, you want CO₂. If you want a chill tank that doesn’t demand weekly attention, skip it.

Regulator choice matters more than most of the other kit. Cheap single-stage regulators do end-of-tank-dumps that kill fish. CO2Art Pro-SE is the floor; anything cheaper is a gamble. Full CO₂ kit (regulator, cylinder, tubing, diffuser, drop checker, check valve) runs $250–400. See Best CO₂ system for a planted tank.

If you’re starting out, skip CO₂. Grow low-tech plants for six months, understand your tank, then upgrade. A planted tank without CO₂ can still look stunning. Anubias on driftwood, a wall of Vallisneria, a carpet of moss. CO₂ accelerates everything; it doesn’t invent beauty.

Test kit: the diagnostic you can’t skip

You need to know ammonia, nitrite, nitrate, and pH. Liquid test kits (API Master Kit is the default) are accurate, cheap per test, and take 3 minutes per panel. Test strips are faster and less accurate. They’re fine for quick checks, bad for cycling a new tank.

For a first tank: test twice a week for the first month, then weekly. Log results. Trends tell you what’s happening; individual readings don’t.

Add a GH/KH test kit separately if you plan to keep shrimp (GH matters for molting) or run CO₂ (KH stability prevents pH crashes). See Best test kit for a planted tank.

What you don’t need

Airstones. Planted tanks are oxygenated by plants during the day. An airstone running during lights-on outgasses CO₂ (bad for plant growth). Only useful in emergencies (power-out recovery) or at night in densely-planted tanks.

A UV sterilizer. Unless you have a specific persistent algae outbreak (green water, ich outbreak). Plants benefit from the microorganisms a sterilizer would kill.

A chiller. Unless you’re keeping cold-water species (axolotls, cherry barbs in a hot room). Most homes stay within tropical range year-round.

A smart controller. Useful on high-tech CO₂ setups where pH-triggered injection adds safety. Unnecessary for low-tech tanks.

Proprietary fertilizer regimens. Brands push complex dosing schedules. Simple all-in-one fertilizers (Thrive, APT Complete) work fine for 90% of planted tanks.

Order of operations: the setup sequence that works

  1. Buy the tank. Let it sit on the stand for a week. Look at it. Plan the aquascape. Do dry-runs with hardscape (wood, rocks). This planning time costs nothing and saves re-planting.
  2. Add substrate. Slope it front-to-back. Don’t flatten it. Visual depth comes from slope and terracing.
  3. Install heater and filter. Don’t plug them in yet.
  4. Add hardscape. Driftwood and rocks should go in before plants, since moving them later uproots everything.
  5. Plant heavy. Denser than feels right. You can always remove later; filling gaps is harder. A new tank with sparse planting grows algae instead of plants.
  6. Fill slowly with dechlorinated water. Place a plate or saucer on the substrate and pour onto it to avoid disturbing your planting.
  7. Plug in heater and filter. Let temperature stabilize before adding anything else.
  8. Cycle fishless with an ammonia source. Add liquid ammonia, ammonium chloride, or food (decomposing). Target 2–4 ppm ammonia. Test every 2–3 days.
  9. Wait. Cycling takes 2–6 weeks. Signs it’s complete: ammonia drops to 0, nitrite drops to 0, nitrate climbs, all within 24 hours of adding the ammonia source.
  10. Water change, then add fish gradually. Start with 1–2 hardy species. Add more in 2-week intervals. Test after each addition.

Cycling: what it is, why it matters

The “nitrogen cycle” is the single most important concept for keeping any fish alive. Short version: fish excrete ammonia (toxic). Bacteria convert ammonia to nitrite (also toxic). Other bacteria convert nitrite to nitrate (mostly harmless; plants consume it and you remove the rest via water changes).

A new tank has no bacteria. Adding fish before the cycle establishes means ammonia and nitrite spike, fish die, and you blame yourself (correctly). “New tank syndrome.”

Fishless cycling (adding ammonia source before fish) is the humane approach. You establish the bacteria before any livestock is at risk. Takes 2–6 weeks. Saves fish lives.

Common first-tank mistakes

The realistic budget

For a 20 gallon planted tank, starting from nothing:

CO₂ adds $250–400 to that. Plan to spend another $20–40/month on fertilizers, test reagents, and plant replacements as you refine.