Walstad
Also sold as dirt · dirted tank · MGOCPM · MGOC · Miracle-Gro Organic Choice Potting Mix · MTS · mineralized topsoil · soil under cap · El Natural · dirt tank · capped soil · Miracle-Gro Organic · Organic potting soil / dirted tank (MGOCPM, Walstad) · Organic potting soil
Synonyms Walstad method
Walstad from generic is a dirted (Walstad) soil. It holds plenty of nutrients, which is what decides whether it suits your plants and your shrimp.
At a glance
| Type | Dirted (Walstad) soil |
|---|---|
| Nutrients | Rich |
| Grain | Fine |
| Brand | generic (Miracle-Gro Organic Choice commonly cited) |
| Effect on pH | Neutral |
| Ammonia when new | Leaches for the first weeks |
| Cap | Needs a sand or gravel cap |
| Shrimp | Suits Neocaridina |
Before it goes in
- Walstad is a base layer. It goes under a sand or gravel cap — used on its own it clouds the water and washes out.
- It is nutrient-rich: root feeders grow in it without root tabs.
- It is pH-neutral: whatever comes out of your tap is what the tank sits at.
- It leaches ammonia for the first weeks. Cycle the tank on it before any shrimp or fish go in — this is the single most common way a new tank on it goes wrong.
- It is rough on fish that sift the substrate. Something finer suits German Blue Ram and Julii Cory better.
- It suits Neocaridina, which want harder water than Caridina do.
What kind of substrate is it?
Dirted (Walstad) soil, fine grain, holding plenty of nutrients.
Does it change pH?
No — it is inert and leaves your tap water where it is.
Does it leach ammonia?
Yes, for the first weeks. Cycle the tank on it before any livestock go in.
Can I use it on its own?
No. It is a base layer and needs a sand or gravel cap over it.
What it goes with
- Root feeders that get the most out of it: Cryptocoryne wendtii, Dwarf Hairgrass Mini, Lobelia cardinalis 'Mini' and Alternanthera reineckii.
- Animals that are fine on it: Betta, Cherry Shrimp, Goldfish and Angelfish.