Loach guide: different types and their role in the tank

Kuhli loach

Kuhli loaches (Pangio kuhlii and relatives) are eel-like, bottom-dwelling fish. They hide by day and come out at dusk to sift through sand and eat leftover food and small worms. Keep them in groups of five or more; they are social and less shy in numbers. They need soft substrate (sand or fine gravel) and hiding spots (driftwood, plants, caves). Peaceful and suitable for community tanks. Role: scavenging, detritus, and character.

Clown loach

Clown loaches (Chromobotia macracanthus) are colourful, active, and grow large — up to 12 inches. They need a big tank (75+ gallons for a group) and live a long time. They eat snails and can help with pest snail control. They are sensitive to ich and poor water quality; quarantine new fish. Role: snail control, activity, centrepiece — but only for large tanks.

Yo-yo loach (Pakistani loach)

Yo-yo loaches (Botia almorhae) are medium-sized, patterned loaches. They eat snails and are more assertive than kuhlis. Keep in groups. They can be boisterous with very shy tank mates. Role: snail control, mid-bottom activity.

Hillstream loach

Hillstream loaches (e.g. Sewellia, Gastromyzon) are flattened, river-dwelling fish. They need strong flow, oxygen-rich water, and smooth rocks to graze biofilm. They are not typical community fish; they suit specialised setups. Role: algae and biofilm grazing in high-flow tanks.

Zebra loach

Zebra loaches (Botia striata) are smaller than yo-yos, with striped patterning. Peaceful, social, and good snail eaters. Suit medium community tanks. Role: snail control, bottom activity, peaceful.

Do loaches clean the tank?

Loaches scavenge and some graze algae, but they do not replace maintenance. They eat leftover food, detritus, and snails — they help, but water changes and filter cleaning are still essential. Do not add loaches solely as "cleaners"; add them because you want the fish.

Quick takeaways

• Kuhli: small, eel-like, peaceful. Groups of 5+. Sand and hiding spots.
• Clown: large, colourful, snail eaters. Need 75+ gallons.
• Yo-yo, zebra: snail control, medium tanks. Keep in groups.
• Hillstream: high-flow, specialised. Not typical community fish.