Setting up a UGF Box the Niskai way!
Hiya folks!
I talked about UGF boxes a bit at the last couple of SKV meetings, and I had to set up a fresh one, so I figured i'd show you how
Niskai Aquatics sets up their UGF boxes for Caridina tanks. (You can do the exact same for Neocaridina tanks, but leave out the soil).
Setting up a UGF box this way allows for both aerobic and anaerobic processes to take place, meaning that both Nitrification and (if you're set up right) denitrification to occur.
And because your buffering soil is in the filter, you don't need to have it as a substrate, eliminating the mess once it degrades. UGF boxes push out a fair bit of flow, so a little soil goes a long way.
You will need:
- UGF Box (any size or style, this tutorial also works for cylindrical UGF containers)
- Aqua Soil (if setting up for softwater caridina)
- Scoria - anything from bunnings works well. Just rinse it thoroughly. You can also use ceramic or sintered glass, but scoria is better and I'll explain why)
- a sheet of coarse sponge
Optional: A better airstone. The ceap ones from these chinese UGF boxes are... 4/10. I upgraded to the Bioscape Tropic slim stones)
Step 1:
Grab your UGF box and set up the plate and uplift. This is pretty straightforward, so I shouldn't need to demo it.
You'll want a quality AquaSoil for pH and KH buffering - I use MasterSoil Next because it's a bit cheaper and works just as well as ADA.
(plus, zero ammonia leaching).
Step 2:
Half fill with rinsed scoria. At this stage, I also pre-seed with a tank-appropriate dose of bio-Boost Foundation (this is optional, but recommended).
Why scoria? A handful of reasons. We'll keep it brief.
- It's extremely cheap
(like, $17 for 20kg of landscaping scoria)
- Surface structure that biofilms actually like
Scoria’s irregular pores and shape create micro-gradients of oxygen and flow that mimic natural streambeds. This supports layered microbial guilds (aerobic on the outside, anoxic within) rather than the uniform pore channels of sintered glass.
- Naturally Mineral Rich
Scoria is volcanic rock, formed when molten lava cools and traps gases. That makes it full of tiny mineral pockets that slowly release trace elements like iron, magnesium, and silica — all useful for plant, shrimp and microbial health. Unlike coral or limestone, it doesn’t raise hardness or alter pH, so it keeps your water chemistry stable over time.
- Better long-term stability
Unlike ceramic or sintered glass that can clog and channel over time, scoria resists compaction. The open pore network keeps flow paths self-cleaning under flow.
- Ecological resonance –
Scoria replicates the natural substrates shrimp evolved on: weathered volcanic gravel and mineral silt. It’s closer to river logic than engineered glass beads.
- It looks cool
Seriously. If you've got a transparent box, you want it to look awesome.
Step 3:
Cut your sponge to size. This UGF box is 15x15cm, and I made a slit to wrap around the uplift.
Step 4:
Add soil. You don't need much. I use about 2-3cm worth. Because UGF boxes move more water than you might think,
everything gets passed through the filter 4-6x an hour. You can add more sponge to the top after the soil, but I prefer to leave them open. Let the shrimp graze.
Slowly fill the box before adding it to your aquarium. It seems counter-inutitive, but trust me on this.
Step 6:
Profit.
That's all there is to it, I swear. Just place it in the tank and attach it to an air pump. You should get nice cross-flow and little bubbles.
For neocaridina, skip the soil step. Add more scoria or sponge if you like. But otherwise, that's it.
