Don't believe the labels and packaging, this light will never be considered adequate for a 20 gallon aquarium. The different lighting modes are very nifty on their own and have cool effects on the tank, but the light bar itself is only 10 inches long. It's not even half the length of most 20-gallon aquariums, but half are very deep -- too deep for this light to illuminate well. The problem is compounded by the fact that it's an LED light, meaning it doesn't emit much outside of the LED panel. It's just a spotlight effect. You will definitely need some other supplemental light source, meaning the special effects produced by that light will be less noticeable at best and cancel out at worst. 20 inches long), you should be fine. But don't buy this for a tank longer than 14 inches or you will be disappointed.
Filter AQUAEL Ultramax 2000
17 Review
π 11W Waterproof Submersible Lamp for Aquariums and Ponds - Clears Green Algae and Purifies Water (HUV-11)
9 Review
Aquarium set 6.8 l (filter, cover, lighting) Tetra Cascade Globe white
24 Review
Phlizon 165W Dimmable LED Aquarium Light For Saltwater/Freshwater Fish Coral Reef (20"X7"X2.4")
10 Review
Mini pump Xiaomi Mijia Electric Pump 1S, plastic, black
55 Review
Efficient 2-In-1 Magnetic Fish Tank Cleaner With Non-Slip Design And Scratch-Free Blades
37 Review
π U-BCOO Aquarium Gravel Cleaner Fish Tank: Manual Siphon for Efficient Filter Gravel Cleaning and Water Change in Tanks
22 Review
Steam cleaner Deerma Deerma DEM-ZQ610 EU, white/red
68 Review