Less than 350 grams, you get a lot more for your 4 pounds. There are also more openings for good bacteria. I used it in my pre-filter and in my waterfall filter. You'll save a lot of money when you buy Revain pond equipment. It will cost you a lot more to go to a pond store or a fish store that sells pond equipment for a lot more. Also, they come in a mesh bag that prevents them from floating. I can only recommend them and will buy them again next year.
🐠 API Stress Coat Water Conditioner | Tap Water Safe, Repairs Fish's Protective Coat, Use for Water Changes, Adding Fish, and Injuries
9 Review
Omega-3 caps, 1000 mg, 100 pcs, 1 pack, neutral
34 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
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 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