
I have been using these with my Koi for many years. This is probably the best product on the market for the cost of changing the water and starting up for use in ponds and aquariums.

EcoBio-Block Stone: Natural Water Clarifier & Odor Remover for Aquariums (Medium) - Treats 15-40 Gallons Efficiently
10 Review

Live Freshwater Aquarium Plants: Dwarf Baby Tears, Hemianthus Callitrichoides, Java Moss In Vitro TC Cup By Greenpro
31 Review

Tetra AquaSafe tap water treatment agent, 5 l
11 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

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

π§² Efficient Magnetic Fish Tank Cleaner: KEDSUM Floating Clean Brush with Handle Design
34 Review

Vacuum cleaner TEQQO Aquastick 3 in 1 Power, grey/turquoise
26 Review