Weekly discus aquarium maintenance: the complete routine

In short

• Daily (2–3 min): observe behavior + check temperature + feed 2–3 times (with one fasting day/week).
• Weekly (45–60 min): a 30% water change + clean the glass + vacuum the substrate + test 4 parameters (NH3, NO2, NO3, pH).
• Monthly (15–30 min extra): clean filter hoses + check equipment + clean the outside glass + adjust décor.
• Quarterly: clean mechanical filter media (sponges) in TANK water, NEVER under the tap.
• Water to add: always dechlorinate + match temperature within ±1 °C (±2 °F) of the tank.
• Essential tools: a dedicated bucket (15–20 L / ~4–5 US gal), a vacuum hose, a glass magnet, a digital thermometer, a drop-based test kit.

💱 The routine applies everywhere. Tool and product prices vary a lot by country, so we don't publish fixed international prices. Where a Romania figure appears (monthly cost), it's clearly labelled as a Romania estimate.

What you'll learn

Proper maintenance is the bridge between setup and the long-term routine — the difference between a tank that thrives for 10 years and one with recurring problems. Discus (Symphysodon) are sensitive to water quality and stable parameters — without a weekly routine, nitrate climbs, biofilm builds up and immunity drops. This guide gives you the complete day-by-day calendar, the minute-by-minute routine for the weekly water change, the tools you need and the mistakes to avoid.

Maintenance calendar — by frequency

Daily (2–3 minutes)

💡 Fasting day: once a week (often Sunday) — no food or a minimal amount. Prevents hepatic obesity and constipation, especially on a beef-heart diet.

Weekly (45–60 minutes)

Monthly (15–30 minutes extra)

Quarterly (every 3 months)

The weekly water-change routine — step by step (45 min)

Before you start — preparation (5 min)

Tools on the table:

1. A dedicated aquarium bucket (15–20 L / ~4–5 US gal) — never used with detergent
2. A vacuum-pump hose (gravel cleaner)
3. A glass magnet
4. A digital thermometer
5. A drop-based test kit (NH3, NO2, NO3, pH)
6. Dechlorinator (a water conditioner)
7. A dry towel or cloth

New water (in another clean bucket):

• Tap water at the tank's temperature ±1 °C (±2 °F)
• Check with the thermometer — use a hot/cold tap mix
• Add dechlorinator at the dose on the bottle (for example, a 30% change of a 200 L tank = ~60 L / 16 US gal of new water)
• Stir and let it sit for 5 min

Step 1: Clean the glass (5 min)

• Use a glass magnet (inner + outer halves, attracted through the glass)
• Run it over ALL walls, including the back glass
• The loosened algae will fall onto the substrate → vacuumed in step 2

⚠️ Don't use a detergent sponge. Ever. Detergents are fatal.

Step 2: Vacuum substrate + drain 30% of the water (20–25 min)

Use a vacuum-pump hose (gravel cleaner):

1. Start the siphon — prime the hose until the water flows (or use the priming pump)
2. Vacuum zone by zone — press the pump into the substrate, let it suck up the debris, lift
3. For bare-bottom: vacuum directly above the bottom
4. For fine sand: hold the pump 2–3 cm (~1 in) above, don't blow sand into the filter
5. Continue until you've removed 30% of the total volume (200 L → 60 L / 16 US gal removed)
6. Where it goes: bucket → drain (nitrate-rich water is fertilizer for outdoor plants!)

🧮 Calculate the change volume correctly with the water-change calculator — find the exact amount based on nitrate.

Step 3: Add new water (10 min)

• Check the temperature again, new water vs tank (±1 °C / ±2 °F)
• Pour slowly, over a plate or rock → don't disturb the substrate
• Never directly over the discus (stress + possible injury)
• Check the water level matches the mark

Step 4: Test parameters (10 min)

Use a drop-based master test kit (test daily only in the first 6 weeks):

Step 5: The log (2–3 min)

Note in a log (digital or paper):

• Date + time
• Volume changed (%)
• Parameters before and after
• Discus observations (appetite, behavior, warning signs)
• Changes made (new catappa leaves, plants added, etc.)

Why the log matters: when problems arise, the log tells you EXACTLY when it started and what changed.

Essential tools

A complete weekly-maintenance kit: a dedicated 15–20 L (~4–5 US gal) bucket, a vacuum-pump hose (gravel cleaner), a glass magnet, a digital thermometer, a drop-based master test kit, and a dechlorinator. Useful extras: a fish net (for emergencies), long planting tweezers (50–60 cm / ~20–24 in) and curved plant scissors.

Water changes — frequency vs amount

📚 For details by profile, see the guide How often to change discus water.

Common maintenance mistakes

❌ "I clean the filter sponge under the tap to get the dirt out" — chlorine kills nitrifying bacteria. The tank enters a mini-cycle (raised ammonia/nitrite) for 7–14 days. NEVER tap water on filter media.

❌ "I don't test the water because the discus look fine" — ammonia/nitrite cause harm before visible symptoms. By the time you see behavioral problems, toxicity is already advanced.

❌ "I change 80% of the water once a month" — big parameter swings (pH, TDS, temp) stress discus more than small frequent changes. Max 50% at once.

❌ "I add tap water straight in, the conditioner is marketing" — chlorine and chloramine in tap water are fatal at common municipal concentrations (about 0.2–1 mg/L). Dechlorinator is cheap and essential.

❌ "I vacuum the entire substrate weekly" — nitrifying bacteria live on the substrate too. Vacuum ONLY the visibly dirty areas, not all of it.

❌ "I also use the bucket for laundry" — even microscopic detergent traces kill fish. The aquarium bucket must be 100% dedicated.

❌ "I don't keep a log, I remember the parameters" — after 3 months you can't remember the trends. When a problem appears, you can't investigate.

❌ "I add new water straight in, it's tap water anyway" — cold water (15 °C / 59 °F in winter) into a 29 °C (84 °F) tank = thermal shock, predisposes to Ich.

Vacation maintenance — solutions

Away 3–7 days:

• ✅ Pre-change 30% of the water the day before you leave
• ✅ Clean the glass + vacuum the substrate before leaving
• ✅ Feed normally on the morning you leave (DON'T overfeed "to last")
• ✅ Ask a neighbor/friend just to check that the filter/heater are running
• ✅ Adult discus tolerate 5–7 days without food (even beneficial — a natural fast)

Away 7–14 days:

• ✅ All of the above +
• ✅ An automatic feeder — don't use it for the first time — test it for 2 weeks beforehand
• ✅ Ask an experienced person to do one 20% water change midway

Away 14+ days:

• ✅ Ask an experienced person to do the weekly maintenance
• ✅ Leave written instructions + backup phone numbers

❌ Don't leave it unsupervised beyond 14 days — the heater can fail, a power cut, a filter blockage.

Final checklist — weekly maintenance

Every week, tick:

• ☐ Bucket of dechlorinated water prepared, temperature ±1 °C (±2 °F)
• ☐ Inside glass cleaned with the magnet
• ☐ Substrate vacuumed + 30% of the volume drained (using the gravel cleaner)
• ☐ New water added slowly, without disturbing the substrate
• ☐ 4 parameters tested: NH3, NO2, NO3, pH
• ☐ Logged: date, parameters, discus observations
• ☐ Thermometer, filter, heater checked working
• ☐ Dead plant leaves or visible debris removed
• ☐ Fasting day checked (1×/week, no food or a minimal amount)

What to do next

📚 Learn more: How often to change discus water — the exact calendar by age stage.

🧮 Calculate: Water-change calculator and monthly cost calculator — find the change volume and the monthly maintenance cost.

🛒 Buy: Maintenance tools and water treatment — a complete kit for the weekly routine.