Hillstream Loach
Sewellia lineolata
Also known as Reticulated Hillstream Loach, Butterfly Loach, Tiger Hillstream Loach
Edited by Ivan F. · Reviewed
Beginner verdict
A small, flattened loach shaped like a tiny stingray that clings to rocks in fast, oxygen-rich water. It needs strong flow, cool temperatures and a mature tank with plenty of biofilm, so it is not a typical community fish. Set up a river-style tank and it thrives.
Care at a glance
- Min tank size
- 18 US gal
- Footprint
- 30 x 12 in
- Temperature
- 68–75 °F
- pH
- 6–7.5
- Hardness
- 1–10 dGH
- Swim zone
- Bottom
- Min group
- Single fish
- Lifespan
- Not well documented
Hillstream Loach tank mates and swim zone
Bottom
Spends most of its time in this part of the tank.
Paracheirodon innesi
Hyphessobrycon amandae
Hyphessobrycon herbertaxelrodi
Trigonostigma heteromorpha
Danio rerio
Tanichthys albonubes
Paracheirodon axelrodi
Their temperature ranges barely overlap, so you will have little room for error.
Hemigrammus erythrozonus
Their temperature ranges barely overlap, so you will have little room for error.
Boraras brigittae
Chili Rasbora is small and shy, and is easily outcompeted for food by Hillstream Loach.
Trigonostigma espei
Their temperature ranges barely overlap, so you will have little room for error.
Ancistrus cirrhosus
Their temperature ranges do not overlap, so one of them would always be stressed.
Mikrogeophagus ramirezi
Their temperature ranges do not overlap, so one of them would always be stressed.
Melanotaenia boesemani
Their temperature ranges do not overlap, so one of them would always be stressed.
Hillstream Loach feeding and care
How to feed
- Let it graze biofilm and algae on smooth rocks and glass.
- Add algae wafers and small frozen foods such as daphnia.
- Feed small portions you can see finished within a couple of minutes, because overfeeding fouls the water fast.
Telling males from females
Best judged from above: females have a broader, rounder body, while males look slimmer with a blunter head.
Hillstream Loach care mistakes to avoid
- Plan on one as the centerpiece of the tank, and read the tank-mate lists before adding others.
- Provide strong flow. It needs clean, fast, well-oxygenated water.
- Keep the water cool, because warm tanks hold less oxygen and stress it.
- Add it only to a mature tank, since it grazes biofilm that new tanks lack.
- Check your tank before you buy. Our sourced minimum is 18 US gallons.
Hillstream Loach tank setup
A forgiving setup with room for a small community.
TankAt least 18 US gal (68 L), 75 x 30 cm
The smallest tank our sources give for Hillstream Loach. We list only tanks that hold this volume (allowing 10%, so a standard size counts) and have at least this much floor.
Picks for Spain are still being checked. The options below are for the US, and we have not confirmed that they are sold in Spain.
Aqueon Standard Glass Aquarium 20 Long US
Aqueon Standard Glass Aquarium 29 Gallon US
Why we chose these (Best 20-Gallon Fish Tank: 20 Long or 29?). Nobody here has used or tested them.
Starter kitA kit with the tank, filter and light in one box
We list only kits whose tank fits Hillstream Loach, up to twice its minimum volume. A kit whose heater has a fixed setting shows only when that setting is inside Hillstream Loach's temperature range.
None of our picks for Spain suits this species. The options below are for the US, and we have not confirmed that they are sold in Spain.
Tetra Complete LED Aquarium Kit 29 Gallon US
Check the heater's setting
Why we chose these (Best Aquarium Starter Kit: What to Look For). Nobody here has used or tested them.
FilterHang-on-back or large sponge filter
Easy to maintain and strong enough for a community without blasting the fish.
Seachem Tidal 55 Power Filter US
Marineland Penguin PRO 175 Power Filter US
Eheim LiBERTY 130 Hang-on Filter Spain
Seachem Tidal 35 Power Filter Spain
Why we chose these (Best Filter for a 20 to 29-Gallon Tank). Nobody here has used or tested them.
HeaterKeep it at 68–75 °F (20–24 °C)
Adjustable heater, about 5 W per gallon: 100 W at 20 gallons, about 150 W at 29. Enough power to hold a stable temperature in most homes. Size up for a cold room.
Aqueon Pro Adjustable Heater 100 W US
Aqueon Submersible Glass Heater 100 W US
Eheim Thermocontrol e 100 Heater Spain
Tetra HT 100 Electronic Heater Spain
Why we chose these (Best Heater for a 20 to 29-Gallon Tank). Nobody here has used or tested them.
Water conditionerDechlorinator such as Seachem Prime
Tap water contains chlorine or chloramine that harms fish.
Seachem Prime US
Fritz Complete Water Conditioner US
API Betta Water Conditioner US
sera aquatan Spain
Tetra AquaSafe Spain
Sold at Kiwoko · Sold at Tiendanimal · Sold at zooplus.es · Maker's details
Why we chose these (Best Water Conditioner for Betta Fish). Nobody here has used or tested them.
Test kitLiquid kit such as API Freshwater Master
Tracks ammonia, nitrite, nitrate and pH while the tank cycles.
API Freshwater Master Test Kit US
API General & Carbonate Hardness Test Kit US
See it at The Shrimp Farm (a retailer; affiliate link) · Sold at Bulk Reef Supply · Maker's details
sera aqua-test box (Cl) Spain
JBL PROAQUATEST COMBISET Plus NH4 Spain
Why we chose these (Best Test Kit for a Freshwater Aquarium). Nobody here has used or tested them.
SubstrateSmooth gravel
We are still choosing products for this.
Hiding places and decorNeeds a mature tank with plenty of algae-covered rocks; use only aged driftwood because new wood leaches tannins.
We are still choosing products for this.
PlantsMostly safe with live plants
Cycle the tank before adding animals. See our guide on how to cycle a fish tank.
Where to buy Hillstream Loach
Stores that list it under the same scientific name as this page. Links marked as affiliate links may earn us a commission. We have not bought from them, so check each store's own terms.
See it at The Shrimp Farm (a retailer; affiliate link)
We have not found a store that sells Hillstream Loach under its scientific name yet. We add stores as we confirm them.
Live animals and plants travel by courier. Check the store's live-arrival guarantee, and only buy once your tank has cycled (see how to cycle a fish tank).
Some US states restrict certain species. Check our US state aquarium rules table and your state's own rules before you buy.
Hillstream Loach FAQ
What size tank do Hillstream Loaches need?
Our sourced minimum is 18 US gallons (68 liters), with a footprint of 75 x 30 cm. A bigger tank is always easier to keep stable.
How many Hillstream Loaches should I keep?
One is fine in a tank this size. Add more only with plenty of extra room and cover.
What can live with Hillstream Loaches?
Good matches on our list include Neon Tetra, Ember Tetra and Black Neon Tetra. Avoid Endler's Livebearer and Molly.
How long do Hillstream Loaches live?
Lifespan is not well documented for this species. Stable water and a good diet help any animal live longer.
Can hillstream loaches live in a normal community tank?
Only if the tank has strong flow, cool water and high oxygen. Most warm, gently filtered community tanks do not suit them.
Hillstream Loach facts and sources
- Family
- Gastromyzontidae
- Native to
- Vietnam
- Adult size
- 2.6 in (6.5 cm)
- Temperament
- Peaceful
- Social needs
- Solitary/Centerpiece
- Diet
- Algae Grazer
- Water flow
- High Flow
- Substrate
- Smooth Gravel
- Live plants
- Mostly Safe
- Shrimp
- Adult Shrimp Only
- Fin nipping
- None
- Vulnerable to nippers
- No
- Breeding
- Difficult in Home Tanks
Sources
- Seriously Fish: Tank size, water ranges and behavior
- FishBase: Cross-check of water ranges and size
Lifespans are approximate and come from aquarium care guides, because these databases rarely publish them.
Where sources differ, we show the Seriously Fish aquarium figures.
Spotted something wrong? Report a parameter correction. For a sick fish, see our veterinary disclaimer.