In this video I build a brand new Caridina shrimp tank using an acrylic under gravel filter (UGF) box, and I’ll be honest—this is still one of my favourite ways to filter high-end Caridina from my own experience. The set is simple (UGF box, plate, lifting tube) and I load it with ADA Amazonia, sprinkle bacterial powder, fill with RO water, hook up an airstone, and then I literally forget the tank exists for about a month. The whole point is to force water through the soil so the soil works harder: better buffering, better nutrient dissolving, and loads of biological filtration because the soil becomes your filter media. After cycling, I took it further and turned it into a planted setup using acrylic trays so I can keep plants contained and movable. I added CO2 to speed growth and ended up with a proper jungle—plus my signature coconut arches with moss, and even a coconut shell “bonsai” using Rotala bonsai attached like I normally do with moss. Then I ran a little experiment: CO2 pushed my pH from 5.7 (degassed) down to 5.1 in-tank, which is huge for high-end Caridina. The downside is oxygen at night, so I used a Söchting Oxydator Mini to supply pure oxygen microbubbles. Finally I moved in around 50 Galaxy Tiger shrimp (my favourite Caridina) and I’ll be tracking how they breed and thrive in a low pH, CO2-injected environment.