A trout in the classroom tank needs to stay between 50°F and 55°F (10°C to 13°C), which means a dedicated aquarium chiller is the first and most important piece of equipment you'll source. Trout are coldwater salmonids, and they'll die in water above 60°F. Standard aquarium equipment designed for tropical fish won't work here. The tank setup is different enough from a typical classroom aquarium that it's worth walking through each component in detail.

This guide covers everything from selecting the right tank and chiller to water quality management, feeding, and the release process. Programs like Trout in the Classroom (TIC) run through partnerships with organizations like Trout Unlimited, which provides eggs, guidance, and often some funding, but the equipment selection and daily care fall to the classroom teacher.

Choosing the Right Tank Size and Type

For most classroom setups, a 20-gallon long or 29-gallon aquarium works well. The "long" format (20L is 30 inches x 12 inches x 12 inches) gives more surface area for gas exchange, which matters for trout, which need well-oxygenated cold water.

Avoid tall tanks. A 20-gallon high tank (24 inches x 12 inches x 16 inches) has the same volume but less surface area. Trout are active swimmers and need horizontal space more than vertical depth, especially as they grow from eggs to fry to fingerlings.

If your program runs a full school year with a large class, a 40-gallon breeder (36 inches x 18 inches x 16 inches) gives more room as fish grow. Many experienced TIC teachers recommend this size because overcrowding later in the year is one of the most common problems.

A glass aquarium is preferable to acrylic for this application because the chiller's temperature probe and equipment handles the cold water without any of the clouding that cheaper acrylics sometimes develop over repeated thermal cycling.

The Chiller: The Most Critical Piece of Equipment

No piece of equipment in a trout classroom setup matters more than the chiller. Room temperature water won't work, period. In most school buildings, ambient temperature stays between 68°F and 75°F, which is lethal to trout over time.

The JBJ Arctica DBA-075 (1/10 HP) works reliably for 20 to 40-gallon tanks in a room temperature environment around 70°F. It can hold water at 50°F even when room temperature is in the mid-70s. The IceProbe Thermoelectric Aquarium Chiller is a lower-cost option for tanks under 10 gallons but struggles to hold temperature in a warm classroom, so it's generally undersized for a real trout program.

For a 40-gallon setup with a warmer classroom (75°F or above), the JBJ Arctica 1/5 HP (DBA-150) provides more cooling capacity without running continuously, which extends its lifespan.

Connect the chiller with the manufacturer's tubing to your filter's pump output or a dedicated circulation pump. The chiller cools the water as it passes through, then returns it to the tank. Run the chiller on a controller like the Inkbird ITC-306A so it cycles on only when needed rather than running constantly.

For a broader look at cooling equipment, the best aquarium equipment guide covers chiller options and sizing in more detail.

Filtration for Trout Tanks

Trout produce more waste than most ornamental fish of similar size, and the cold water in a trout tank actually slows the biological filtration bacteria, which prefer warmer conditions. This means you need more filtration capacity than you'd use for a tropical tank of the same volume.

A hang-on-back filter like the AquaClear 50 (rated for up to 50 gallons) works well for a 20 to 29-gallon trout tank. Run it with a sponge pre-filter on the intake to protect small fry and increase biological filtration surface area.

Add a sponge filter driven by an air pump as secondary biological filtration. The Hikari Bacto-Surge Foam Filter (medium or large) in the corner of the tank provides additional bacterial colonies and gentle supplemental circulation. The added aeration from the air pump also helps with dissolved oxygen levels, which trout require in higher concentrations than most aquarium fish.

For a 40-gallon setup, a canister filter like the Fluval 207 provides excellent biological filtration capacity and handles the higher waste load as fingerlings grow.

Aeration and Water Quality

Trout need dissolved oxygen levels above 7 mg/L, and preferably above 9 mg/L. Cold water holds more oxygen than warm water, which is one reason trout are coldwater fish. At 50°F, water can hold about 12 mg/L of dissolved oxygen at saturation. At 70°F, saturation drops to about 9 mg/L.

Run an airstone or the sponge filter's air supply continuously. Position the outlet for your HOB filter or canister return so it creates surface turbulence without splashing so much that it deposits water on the classroom floor.

Monitor ammonia and nitrite weekly with the API Freshwater Master Test Kit. Trout are particularly sensitive to ammonia, and even 0.25 ppm can cause gill damage over time. If ammonia rises, perform a partial water change immediately and reduce feeding.

Water changes of 15 to 20 percent per week keep nitrates manageable. Use dechlorinated water chilled to within 2°F of tank temperature before adding it. Adding cold tap water straight from the faucet can shock fish. Let replacement water sit in a bucket with a heater set to your target temperature (or without a heater if tap water is already close) and add Seachem Prime to dechlorinate.

Feeding and Growth Stages

Trout eggs arrive in fall and hatch into alevins, which feed off their yolk sacs and don't need supplemental food. Once the yolk sac is absorbed and they become fry, start feeding.

Use a quality trout pellet like Rangen Trout Starter Crumbles or Purina Aquamax Fingerling Starter 300 in a size appropriate to fish size. Start with a 1.5mm crumble for early fry, moving to a 2mm or 3mm pellet as fish grow. Feed two to three times per day, only what fish eat in about 5 minutes. Uneaten pellets decompose quickly and spike ammonia.

As fish grow into fingerlings (3 to 5 inches), they're close to release size. Most programs release between late winter and early spring, depending on your region and the water temperature of the stocking stream.

For a complete look at what equipment supports this kind of active tank management, the top aquarium equipment overview covers chillers, aeration, and filtration in a practical priority order.

Handling Disease and Common Problems

Fungal infections on eggs are the most common problem in TIC programs. A white cotton-like growth on eggs (saprolegnia fungus) spreads quickly. Remove infected eggs with tweezers immediately to prevent spread.

Keep a UV sterilizer running during incubation if your budget allows. The Coralife Turbo-Twist 3X UV Sterilizer for tanks up to 40 gallons kills fungal spores and bacteria in the water column before they can infect healthy eggs.

Fin rot and gill disease in fry usually indicate poor water quality. Test immediately if fish appear lethargic, have clamped fins, or gather at the surface. The solution is almost always a water change combined with identifying and correcting the root cause (overfeeding, insufficient filtration, or too-infrequent water changes).

Never use salt or standard fish medications in a trout tank without confirming the product is salmonid-safe. Many common aquarium medications are toxic to trout at doses that are safe for tropical fish.

FAQ

Where do I get trout eggs for a classroom program? Most TIC programs work through Trout Unlimited chapters, which partner with state fish hatcheries to provide fertilized eggs in the fall. Contact your state's TU chapter or fish and wildlife department. They provide eggs and often technical support, training, and sometimes equipment.

How cold does the water need to be, and how do I maintain it? Target 50°F to 55°F (10°C to 13°C). Brown trout tolerate up to 68°F briefly, but chronic exposure above 60°F causes stress and death. Keep your chiller set to 52°F for a good safety margin. Use a digital aquarium thermometer like the Zacro LCD Digital Thermometer to monitor temperature continuously.

What happens if the power goes out overnight? In a well-insulated tank in a room at 70°F, water temperature will rise about 1°F per hour without the chiller running. An 8-hour outage can push a 52°F tank to 60°F, which is stressful but survivable if it happens once. Having a battery-powered air pump ensures oxygenation continues even if the main filter and chiller go down. The AQUANEAT USB Aquarium Air Pump works on a USB battery bank.

Can students handle the fish? Handling is discouraged. Trout have sensitive slime coats that protect against disease, and warm human hands cause thermal stress at the contact point. If transfer is necessary for tank maintenance, use a fine mesh net and move fish quickly. Never handle them with bare hands.

Wrapping Up

A successful trout classroom setup comes down to three things: stable cold temperature, excellent water quality through adequate filtration, and appropriate feeding. The chiller is the investment that makes everything else possible. Beyond that, consistent monitoring with a reliable test kit, weekly water changes, and careful attention during the egg and alevin stages give you the best odds of having healthy fish to release in spring.