This is the material that good manufacturers use for most aquariums. This has been tested on 750 gallon tanks. Make sure you cover your tank, you can use emergencies I've heard from others.
EcoBio-Block Stone: Natural Water Clarifier & Odor Remover for Aquariums (Medium) - Treats 15-40 Gallons Efficiently
10 Review
π API Stress Coat Water Conditioner | Tap Water Safe, Repairs Fish's Protective Coat, Use for Water Changes, Adding Fish, and Injuries
9 Review
Tetra AquaSafe tap water treatment agent, 5 l
11 Review
ACCU-CLEAR Water Clarifier for Freshwater Aquariums - Quickly Clears Cloudy Water, Ideal for Weekly Use
9 Review
Efficient 2-In-1 Magnetic Fish Tank Cleaner With Non-Slip Design And Scratch-Free Blades
37 Review
Jasonwell Magnetic Aquarium Fish Tank Glass Algae Cleaner - Floating Brush (L Size)
37 Review
π U-BCOO Aquarium Gravel Cleaner Fish Tank: Manual Siphon for Efficient Filter Gravel Cleaning and Water Change in Tanks
22 Review
𧲠Efficient Magnetic Fish Tank Cleaner: KEDSUM Floating Clean Brush with Handle Design
34 Review