My DIY main and 1st AP system - Learn from the mistakes I made with this system
My small, cheap, simple, basic DIY AP system
Info for beginners: Number of fish you can keep does NOT just depend on fish tank size. It mainly depends on the amount of aeration and amount of filtration, ie grow bed size. If your fish will be large enough to eat or messy like goldfish, then start with no more than 1 fish per 20L (5.3 gallons) of GROW BED volume, is my advice.