My advice: Don't worry. I put it in and it doesn't harm the algae. With four days, 1/4 of the additive should be injected in the first four days, and the filter is only good for seven days - after seven days it should basically be disposed of. The addition didn't help and neither did the algae filter in my Biorba. I think it's better to spend money on a regular filter. I was really upset that it didn't work so I put some activated charcoal in the filter (after letting it sit for a week) and reused it to make my money out of it. Good cleaning with a white nylon pad and some elbow grease. Won't buy this again!
ACCU-CLEAR Water Clarifier for Freshwater Aquariums - Quickly Clears Cloudy Water, Ideal for Weekly Use
9 Review
Tetra AquaSafe tap water treatment agent, 5 l
11 Review
🐟 Two Little Fishies Marine Snow ATLMSPD4, 16.9 oz
10 Review
12 Count Greenpro Root Tabs Fertilizer Tablets: Ideal For Aquariums, Ponds & Water Gardens!
26 Review
Efficient 2-In-1 Magnetic Fish Tank Cleaner With Non-Slip Design And Scratch-Free Blades
37 Review
Steam cleaner Deerma Deerma DEM-ZQ610 EU, white/red
68 Review
🐠 U-BCOO Aquarium Gravel Cleaner Fish Tank: Manual Siphon for Efficient Filter Gravel Cleaning and Water Change in Tanks
22 Review
🧲 Efficient Magnetic Fish Tank Cleaner: KEDSUM Floating Clean Brush with Handle Design
34 Review