How to set up a planted aquarium: from substrate to first fish

Choose a size and a style

A tank around 60 cm (24 in) long, roughly 60 l or 16 US gallons, is a sensible first planted tank. In a small volume temperature, pH and nutrients swing faster and mistakes are diluted less, so a nano tank is less forgiving than its size suggests.

Pick your style up front, because it decides the plants and the equipment. Strong light and fast-growing plants need injected CO₂ and regular fertilizing. A low-tech tank runs without CO₂, grows more slowly and is more forgiving. The common styles:

• nature aquarium – a landscape of rock and wood with plants in asymmetric groups,
• iwagumi – rocks are the structure, with only one to three plant species, often a low carpet,
• Dutch – plants only, no rock or wood, many species side by side like a flower bed,
• low-tech – no injected CO₂, lower light and slow growers such as anubias, java fern, cryptocorynes and mosses,
• shrimp tank – for Neocaridina such as cherry shrimp, which want more neutral, harder water than most planted tanks: pH around 6.5–7.8 and GH around 6–12.

Aquasoil or inert substrate

Aquasoil carries nutrients for plants, usually lowers KH and pH, and most brands release ammonia for the first few weeks. That is why you change water often at the start and wait before adding livestock. Both the nutrients and the effect on pH fade over time.

Inert substrate – sand or gravel – leaves the water alone but holds almost no nutrients, so you supply them with fertilizer. Neocaridina shrimp do fine on inert substrate and do not need aquasoil.

Slope the substrate from the front glass to the back, about 3–4 cm at the front and 6–9 cm at the back. The slope adds depth and gives taller background plants room for roots. The volume and substrate calculator tells you how many litres and bags you need.

Hardscape: rock and wood

Build the layout while the tank is dry and keep moving pieces until it works. Every rock and branch has to sit firmly so nothing shifts once the water is in.

Limestone raises KH, GH and pH, and that includes the popular Seiryu stone. To check a rock, drip vinegar on a clean, dry face – if it fizzes, it contains calcium carbonate. No fizz is not proof, since vinegar is a weak acid; you can also soak the rock in water for a few days and compare the pH before and after. Keep limestone out of soft-water tanks, or use it knowing the hardness will creep up.

Soak wood before it goes in, from a few days to several weeks depending on how dense it is. It releases tannins that tint the water brown and make it slightly more acidic, and it floats until it is waterlogged. The white film that often grows on new wood in the first days is usually harmless and fades on its own.

Planting

Before planting, add just enough water to cover the substrate, a few centimetres (an inch or so) at most. Plants stay put and tweezers work best in shallow water.

Plant densely from day one. Fast growers such as water sprite or water wisteria (Hygrophila difformis) take nutrients away from algae, and you can swap them later for the plants you want to keep.

• do not bury the rhizome of anubias, java fern or Bucephalandra – it rots in the substrate; tie them to wood or rock with thread or fix them with super glue gel (cyanoacrylate), the same way as mosses,
• tissue-culture (in vitro) plants come free of snails, algae and pesticides, but they are smaller than potted plants.

Filling and the first days

Pour the water slowly onto a saucer, a bowl or your hand so the stream does not dig into the substrate or pull plants out. Treat tap water with a conditioner that handles both chlorine and chloramine – both harm fish and the bacteria in the filter.

Cloudy water in the first days is normal. It usually clears within a few days; with aquasoil a water change speeds it up.

The first four weeks

• light: 6 hours a day for the first two or three weeks, then add half an hour a week up to 8 hours – a long photoperiod at the start feeds algae,
• CO₂, if you inject it: from day one, but only around the photoperiod – on one to two hours before the lights, off about an hour before they go out, and off overnight (a solenoid on a timer),
• CO₂ target: 20–30 mg/l (ppm); adjust in small steps and wait at least a day between changes,
• water changes: with aquasoil 25–50 % several times a week for the first three to four weeks; with inert substrate less is needed, typically around 30 % once a week,
• fertilizer: with aquasoil dose lightly at first, since it supplies nutrients on its own; with inert substrate dose at a reduced level from the start.

A CO₂ reading is only an estimate. A drop checker is right only with 4 dKH reference solution, not tank water, and it can lag by several hours; aim for green, not yellow-green. If fish gasp at the surface, switch the CO₂ off straight away, do a large water change with conditioned water at the same temperature and increase surface agitation.

Add livestock only after the cycle, once ammonia and nitrite read zero for several days. With CO₂, the drop checker should be green, not yellow, before they go in, and keep a close eye on them for the first few days. Add Neocaridina shrimp only to a cycled tank, ideally one that has been running for several months.

Day one: a photo and a log

Setup day is day one. Take a photo from the front, from the same spot and height you will use every time after – comparing month one with month twelve shows more than memory can. In SUISO the setup date is day one of the journal, and the app reminds you to take a photo on days 7, 14, 30, 60, 90, 180 and 365.

Log water changes, ammonia, nitrite, nitrate, pH and KH readings, photoperiod, CO₂ settings, fertilizer doses and the day livestock went in. When algae or plant problems appear, you can see what changed in the days before instead of guessing.