WIO > Riverbed

WIO Riverbeds are pre-blended substrates — several grain sizes and several colors mixed in one bag, arranged to look like a stretch of natural riverbed rather than a uniform layer of sand. The idea is that real rivers are never one grain and never one color, and a substrate that is both reads as artificial no matter how good the rest of the scape is.

What you are actually buying

A bag of fines, mid-grade grit, small pebbles and the occasional larger stone, blended in proportions meant to imitate a specific kind of watercourse. You spread it and shape it, and the variation does the work that would otherwise take you an afternoon of mixing three products by hand and still not getting right.

They are not active soil. There are no nutrients in them, no buffering capacity, and no cation exchange to speak of. If you are planting heavily, treat a Riverbed as an inert substrate and plan for root tabs or a soil layer capped beneath it.

Choosing a color family

The names are the useful part, because they run across the whole WIO range. Silver Shine, Tan Savage, Red Dusk, Midnight Veil, Black Allure, Amber Dragon, Jade Bliss and Pale Ethereal are color families, not just product names — and there are matching stones, sands and boulders in several of them.

That is the practical reason to buy into the system rather than picking the prettiest bag: a Black Allure riverbed under Black Venom stone looks deliberate. A Black Allure riverbed under a random gray rock looks like two decisions made on different days.

Broad guidance on what the families do in a tank:

• Pale Ethereal, Silver Shine, Tan Savage — light beds. They bounce light back up into the tank, make a small tank look larger, and show off dark fish. They also show every scrap of detritus, so they suit tidy, well-maintained setups.
• Black Allure, Midnight Veil — dark beds. Color on fish and shrimp intensifies over dark substrate, which is a real effect and not a trick of the eye. Debris hides. Plants read more vividly against them.
• Red Dusk, Amber Dragon, Jade Bliss — warm and colored beds. Distinctive, and they commit the whole tank to a palette, so pick the hardscape at the same time.

Sizes and how much you need

These come in 1.5, 3 and 5 kg bags. As a rough guide, allow around 1 kg per gallon for a two-inch bed in a standard-footprint tank, and more if you intend to slope it. A 5 kg bag is a nano tank's whole substrate; a four-foot tank will want several.

Buy the whole amount at once. Blended products vary slightly between production batches, and a bed topped up six months later can show a visible seam.

One thing to check yourself

WIO does not publish chemistry data for these blends. If you keep soft-water species — Caridina shrimp, wild bettas, chocolate gouramis, discus, or anything you are breeding in acidic water — test a sample before committing: put a few drops of white vinegar on a dry pinch of the substrate. Steady fizzing means carbonate content, which will raise hardness over time. No reaction means it will leave your parameters alone. Ten seconds, and it is the difference between a stable tank and a slow mystery.

For community fish, livebearers and Neocaridina shrimp in San Diego's already-hard water, this is not something to worry about.

See it before you commit

Substrate color photographs badly and changes completely once it is wet. We keep WIO on the floor at the Convoy store and we are happy to wet a sample so you can see what it actually looks like under water rather than under a camera. Both stores test water for free, and it is worth knowing your KH before choosing a bed. See also the complete WIO River Kits, which pair a riverbed with matching stone in one box.