Tank size sets the baselines
Heater watts roughly track gallons: 50W for 10, 100W for 20, 150W for a 40-breeder. Filter turnover lands around 4–6× for low-tech, 8–10× for heavily planted.
Start with the tank
The right gear
for your
exact
setup.
Four answers about the tank (size, planting, livestock, experience) point to one matching setup: filter, heater, light, substrate, and CO₂ when the planting level calls for it. Every pick is sized to the tank.
20 gal
the sweet-spot starter size
100W
heater watts for a 20-gallon
8 hr
lights-on per day, low-tech
Matched setup
Fluval 107 · Eheim Jager 100W · Week Aqua P600 Pro
20-gal high-tech, community fish, intermediate
How a planted tank fits together
Size first. Then plants. Then light. Then CO₂.
Gear decisions chain off each other. Tank gallons set heater watts and filter turnover. The plant list sets light intensity. Light sets the CO₂ question. Get the order right and the picks line up.
Plants set the light spec
Anubias, ferns, and mosses thrive at low light. Stems, carpets, and red plants want medium-to-high light with a spectrum that pushes red and blue. PAR matters more than wattage.
Light drives the CO₂ question
Low light, no injected CO₂, and most planted tanks stay stable. Push past medium light and plants out-run what diffuses naturally. CO₂ becomes the bottleneck.
Most-asked questions
The picks people came here for.
Tank size and livestock move every one of these answers.
Filters
Best Filter for a 20 Gallon Planted Tank
Canister, HOB, or sponge. The right pick depends on livestock and how heavily the tank is planted.
Lights
Best Light for a 20 Gallon Planted Tank
Three picks by plant density: low-tech budget, programmable medium-tech, and high-tech for CO₂ tanks.
Heaters
Best Heater for a 20 Gallon Planted Tank
100W is the sweet spot. Why two 50W heaters beat one 100W when livestock matters.
Filters
Best Filter for a Shrimp Tank
Sponge filter or HOB with a pre-filter sponge. The two safe options for baby shrimp.
Lights
Best Light for a Shrimp Tank
One budget LED with the spectrum that shows red and blue colors on neocaridina and caridina.
Filters
Best Filter for a 10 Gallon Planted Tank
Gentle flow that doesn't disturb plants, with enough bio-capacity for a community tank.
Start here
The long-form guides.
Starting from zero. Going low-tech. Building a shrimp nano. When you need a full plan, not a single pick.
Complete guide
Starting a planted tank
Tank, filter, heater, light, substrate. The order they matter, and the picks that won't bite you later.
Read the guideFor beginners
The low-tech planted tank
No CO₂. Modest light. The plants that actually thrive, and the ones to avoid.
Read the guideNano builds
Nano shrimp tank setup
How to build a 5–10 gallon shrimp tank that stays stable and keeps babies alive.
Read the guideThe fastest path
Four questions. One setup. Yours.
Tank size. Planting level. Livestock. Experience. The setup that matches those four: filter, heater, light, substrate, and CO₂.
Run the calculator