How to Set Up Your DeskMate 4.8
This guide starts with the unopened DeskMate bundle and walks you all the way through setting up and cycling the tank. I will show you what comes in the current BRS bundle, what you still need to buy, and what I would check before moving to the next stage.
DM-001 · track overview preview
DeskMate 4.8 Setup Guide
The DeskMate is the smallest of the three beginner tanks on this site. It holds 4.8 gallons total, with a 3.8-gallon display and a 1-gallon rear chamber. That tiny footprint is the whole appeal—but it also means evaporation, temperature, food, and livestock can change the tank very quickly.
Affiliate disclosure: The BRS video and product links in this guide are Impact affiliate links. If you make a purchase after following one, My First Fish Tank may receive a commission at no additional cost to you.
The bundle includes the aquarium, pump, light, filter sock, rock, live sand, biomedia, bacteria, heater, and starter salt. You still need a safe support and power plan, appropriate source water, salinity and temperature measurement, cycle testing, mixing and maintenance tools, replacement salt, and a careful livestock plan.
Stage 1
Plan, unbox, and prepare
Choose a safe place for the tank, inspect everything in the box, figure out where the rear-chamber equipment and cords will go, and gather the water, mixing, and testing supplies you need before you fill it.
Stage 2
Aquascape, fill, and tune
Build rockwork that will not fall over and that you can still clean around. Then add only the sand you need, mix the saltwater outside the tank, fill it slowly, and adjust the equipment and water level.
Stage 3
Cycle and stabilize
Cycle the aquarium without a fish, use your test results instead of guessing, and build a simple routine for this tiny water volume before you add livestock.
DM-002 · stage 1
Plan, Unbox, and Prepare Your DeskMate 4.8
By the end of this stage, the empty tank should be in its permanent location, every part should be inspected, the rear chamber and cords should make sense, and your water and testing supplies should be ready.
A little planning while the aquarium is still empty prevents the most common setup frustrations: a poor location, missing tools, inaccessible equipment, unsafe cord routing, and an interrupted first fill.
Before you start
| Confirm | What you should have |
|---|---|
| Inside the current bundle | DeskMate CLASSIC aquarium, adjustable nozzle, return pump, Curve Lite LED, nano filter sock, LifeRock kit, Fiji Pink live sand, ceramic biospheres and mesh bag, 125 mL MicroBacter7, 25W Eheim Jager heater, and 2 kg Aquaforest Reef Salt. |
| Before operation | A level, stable, water-resistant support; safe outlet strategy with GFCI protection where appropriate; drip loops; a power strip positioned away from splash and pooling water; towels; and enough service clearance to remove every rear-chamber item. |
| Before saltwater | Suitable purified source water, a clean mixing container and pump, a calibrated salinity-measuring tool, and an independent thermometer. |
| Before livestock | A reliable way to test and document the cycle. Testing is not optional. |
Choose and verify the location
Set the empty aquarium where you plan to keep it. Confirm that the entire base is supported, the surface is level in both directions, water cannot damage the furniture, and you can reach the pump, filter sock, heater, light, and every cord without moving the filled aquarium.
- Keep it away from unstable furniture, direct sun, heating and cooling vents, and edges where it can be bumped.
- Plan the path for top-off water, water changes, spills, and travel days.
- Keep plugs and power connections away from places where water could collect.
- If you are not confident about the furniture, floor, electrical outlet, or anything else supporting the tank, sort that out before you add water.
Unbox and inspect every component
Work on a clean, soft surface that will not scratch acrylic. Check the panels, bonded seams, orange base, rear chamber, nozzle, pump, light, sock, heater, rock, sand bag, biomedia, bacteria bottle, and salt bag.
- Do not use a metal blade, rough pad, or household cleaner on the acrylic.
- Photograph shipping damage before assembling or wetting the product.
- Confirm the bacteria and salt match the current bundle—not the older video.
- Keep the live-sand bag sealed until you are ready to aquascape and fill.
Dry-fit the rear chamber and maintenance path
Place the pump, nozzle, filter sock, biomedia, and heater in the rear chamber without plugging anything in yet. Make sure water can move through the chamber and that you can still remove the sock, heater, and pump later without taking the whole tank apart.
- Follow each equipment manual for orientation, minimum water level, and clearances.
- Do not force the heater or biomedia into a position that blocks flow or maintenance.
- Route cords so each one can form a drip loop and no plug must sit on the floor.
Gather the missing setup and testing supplies
The bundle includes a lot, but it does not include everything you need. You will still need a way to make saltwater, measure salinity and temperature, test the cycle, replace evaporated water, and handle normal maintenance.
- Prepare suitable purified source water and a clean container and pump for mixing saltwater.
- Have a calibrated salinity-measuring tool and a separate thermometer ready before the first fill.
- Choose a compatible, test-based cycling plan and have the necessary test supplies before adding bacteria or an ammonia source.
- Set aside dedicated towels, a small siphon or water-change tool, and a safe way to add purified top-off water.
Aquascape, fill, and tune the DeskMate with the current rock, sand, and Reef Salt.
DM-003 · milestones 5–6
Aquascape, Fill, and Tune Your DeskMate 4.8
Build rockwork that stays put and leaves room for flow and cleaning. Mix and measure the saltwater outside the aquarium, then fill the tank and learn what the normal running water level looks like.
The supplied rock and 10-pound sand bag are options, not instructions to force every piece and every grain into a 3.8-gallon display.
Build the rock structure outside the tank
Use a clean towel or soft mat to protect the acrylic and rock. Try several arrangements with the two arches and smaller LifeRock piece before transferring anything into the aquarium.
- Keep the structure low enough to leave swimming room and future coral clearance.
- Leave space around the side and rear panels for an acrylic-safe cleaner.
- Preserve an open path for water to move around and through the structure.
- Do not rely on loose sand to stabilize a top-heavy rock stack.
Place the rock and add a maintainable sand bed
Move the finished rockwork into the tank carefully so it does not slide into the acrylic. Add a shallow layer of live sand that you can actually keep clean. You probably will not need the entire 10-pound bag in this tiny display.
- Follow the live-sand bag instructions; do not rinse it with tap water or let it dry.
- Keep sand out of the rear chamber and away from the pump.
- Do not bury the structure in a way that hides instability.
Mix the current Aquaforest Reef Salt
Use purified water in a clean, food-safe container. Warm it, circulate it, and add the Aquaforest Reef Salt slowly. The current bundle includes a 2 kg bag that BRS says can make up to 16 gallons, but the amount you actually use depends on the salinity you measure.
- Calibrate your salinity tool according to its instructions.
- Mix toward the salt manufacturer’s current 33 ppt guidance—about 1.025 specific gravity near normal reef temperature—then confirm with your instrument rather than relying on a scoop count.
- Allow the salt to dissolve fully and verify temperature and salinity before the water enters the aquarium.
- Record the amount of source water and salt that produced the final measured result so future water changes are repeatable.
Older DeskMate material shows different salt quantities and different bacteria. Use the current product labels and the current bundle list.
Fill slowly and tune the system
Place a clean plate or plastic bag over the sand and add measured saltwater slowly to reduce disturbance. Once the rear chamber reaches the correct operating level, start the pump and tune the nozzle.
- Confirm the pump stays submerged and the return chamber does not run dry.
- Set the heater according to its manual and verify actual temperature with the independent thermometer.
- Install the filter sock and biomedia so neither blocks flow or becomes impossible to remove.
- Mark or remember the normal operating water level. Evaporation will appear most clearly in the return area.
- Leave the light off during the initial cycling period unless the chosen cycle method specifically requires otherwise.
Start a fishless, measured cycle and build the daily and weekly routine that keeps this small volume stable.
DM-004 · milestones 7–10
Cycle and Stabilize Your DeskMate 4.8
Do not call the tank cycled just because a certain number of days has passed. Use your test results, then make sure you can keep temperature, salinity, top-off, cleaning, feeding, and water changes consistent before you buy an animal.
Two weeks, one month, or an empty ammonia reading on a single day does not automatically make the aquarium ready. The cycle method, test evidence, stability, and the needs of the first animal all matter.
Choose one fishless cycling method
The current bundle contains 125 mL MicroBacter7. Follow the current bottle instructions, dose for the aquarium’s real water volume after rock and sand displacement, and use the compatible fishless nutrient source specified by the cycling method or product instructions.
- Do not cycle with a live fish.
- Do not use a rotting shrimp as the track’s standard method.
- Do not combine bottled bacteria or ammonia products unless their manufacturers say they are compatible.
- MicroBacter7’s current new-aquarium instructions call for shaking, pre-mixing the dose in aquarium water, avoiding the pump intake, and daily dosing during the initial period. The current label remains controlling.
Write down your cycle test results
Write down the date, ammonia, nitrite, nitrate, temperature, salinity, anything you added, and anything unusual you noticed. The point is to see what the tank is actually doing—not to wait for a date on the calendar and assume it is ready.
| Date | Record |
|---|---|
| Every test day | Ammonia, nitrite, nitrate, salinity, temperature, additions, and observations. |
| Before a readiness test | Confirm test reagents are current, directions are followed, and results are readable. |
| After the final fishless challenge | Document that the selected test dose is processed without measurable ammonia or nitrite rebound under the method’s stated observation window. |
Get into a simple tiny-tank routine
The DeskMate’s open top and small volume make top-off and observation especially important. Replace evaporation with purified freshwater—not saltwater—because salt does not evaporate.
- Daily: check temperature, water level, pump flow, heater behavior, leaks, noise, and anything unusual. Top off to the same mark.
- Several times each week: inspect and clean or swap the filter sock as needed; confirm the return chamber is not collecting debris or running low.
- Weekly: test the parameters appropriate to the tank’s stage, perform a consistent water change, clean acrylic with acrylic-safe tools, wipe salt creep, and inspect cords and equipment.
- Before travel: prove the top-off and feeding plan in advance. An ATO can help stability, but it must be installed, tested, and protected against overfill.
Do not choose the first animal until the tank is ready
A 3.8-gallon display does not give you many livestock options. Before you buy anything, check its adult size, behavior, food, territory, waste, compatibility, and whether it can jump. Remember that the bundle does not include a lid.
- Add a cleanup crew only when the aquarium contains the food that specific animal eats.
- Add livestock gradually; do not treat a packaged “crew” or a gallons-based fish count as an automatic answer.
- Plan acclimation, quarantine or observation, disease response, and feeding before bringing the animal home.
- Use a species-appropriate lid when the stocking plan includes a jump risk.
Coral and anemones are separate decisions
The included light is meant for soft coral and some LPS, but that does not mean every coral will do well under it. Check the exact animal’s light, flow, placement, feeding, aggression, and stability needs. And no, an anemone is not the automatic final step of setting up this tank.
Use the guide that answers your next question
Come back to the DeskMate overview whenever you are not sure what to do next.