🧷 Essential Aquarium Equipment — Deep Guide

Legend:
🎯 purpose • 📏 sizing rule • ⚠️ pitfall • 🔁 maintenance • 🧪 testing • 🤖 automation • 🛡️ safety

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1) Core Life-Support (all tanks)

• 🧱 Tank + Stand — 🎯 hold water safely, keep level
  📏 Full-contact top preferred (especially >55g). Tall tanks need stiffer stands.
  ⚠️ Never shim the tank; shim the stand.
  🔁 Recheck level after first fill and a week later.
• 🛡️ Lid/Cover — 🎯 stop jumpers, cut evaporation/salt creep
  📏 Tight mesh/solid lid; leave room for gas exchange.
  ⚠️ Saltwater fish are Olympic jumpers—covers are functionally essential.
• 🌀 Filtration (bio + mechanical) — 🎯 keep NH₃/NO₂⁻ at 0, trap debris
  📏 Turnover: Fresh 4–8×/hr • FOWLR 6–10×/hr (plus powerheads) • Reef in-tank circulation 20–30×/hr.
  ⚙️ Types: sponge (gentle bio), HOB (simple), canister (media volume), sump (max volume / hides gear).
  🧱 Media order: coarse → medium → fine (temporary) → bio → chemical (optional).
  ➕ Add a prefilter sponge to any intake (keeps canister guts clean, protects fry/shrimp).
  ⚠️ Don’t replace all media at once; you’ll crash the cycle.
• 🔥 Heater (+ 🌡️ thermometer) — 🎯 stable temperature
  📏 3–5 W/gal (cool rooms → 5 W/gal). Use two smaller heaters on larger tanks for redundancy.
  ⚠️ Place near flow; unplug during water changes.
  🛡️ Consider a heater controller to prevent “stuck-on” failures.
  ❄️ Hot rooms/reefs may need fan/chiller.
• 💡 Light — 🎯 see fish; grow plants/corals if needed
  📏 Fish-only = modest. Planted: match PAR/coverage to plant demand. Reef: match coral PAR.
  🌿 Planted PAR (at plant tops): ~40–80 low, 80–150 med, 150–250 high.
  🪸 Reef PAR (at coral): Softies 80–150 • LPS 120–200 • SPS 200–350.
  ⚠️ Spread matters: choose fixtures that cover the footprint, not just the length.
• 🧪 Test Kits — 🎯 verify stability
  Fresh/Brackish: NH₃/NH₄⁺, NO₂⁻, NO₃⁻, pH (KH/GH helpful).
  FOWLR/Reef: add salinity, alkalinity, (Reef also Ca, Mg, PO₄).
  🔁 Replace reagents 6–12 months; check expiration dates.
• 🧴 Water Conditioner — 🎯 neutralize chlorine/chloramine
  📏 Dose for full tank volume if adding directly during refill.
  🛟 Keep an ammonia-binding conditioner for emergencies.
• 🪣 Water-Change Tools — 🎯 cleanly remove/add water
  📏 Gravel vac/Python, “fish-only” buckets, towels.
  🤖 A sink-to-tank hose saves 10–20 min/week.
• 🧽 Algae Scraper/Magnet — 🎯 clear glass/acrylic
  ⚠️ Use plastic blades on acrylic; razor is fine on glass.
• 🔌 Power & Safety — 🎯 prevent shocks/fires/water damage
  🛡️ GFCI/AFCI, drip loops, quality power strip; label plugs.
  🔋 Battery air pump/UPS = oxygen during outages.
  💧 Leak sensors & a tray/mat under the stand.

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2) By Water Type (what’s added)

🟢 Freshwater (low–high tech)

• ✅ All core items above.
• 🌿 (Optional) Plant ferts/CO₂ for high-tech.
• 🧪 KH/GH tests if you remineralize/adjust hardness.

🟤 Brackish

• 🧂 Marine salt mix (not “aquarium salt”).
• 🔬 Refractometer (best) or hydrometer to set SG ~1.003–1.015 (species dependent).
• 🚰 RO/DI helpful if tap is hard/problematic.
• 🤖 ATO nice-to-have for salinity stability.

🔵 Saltwater (FOWLR)

• 🚰 RO/DI system (strongly recommended).
• 🧂 Salt mix + 🔬 refractometer (calibrate with 35-ppt solution).
• 🪨 Live/dry rock (biofilter) + optional sand.
• 🌊 Powerheads to reach 10–20× total circulation.
• 🧪 Add alkalinity test.

🟣 Reef (softies/LPS/SPS)

• ✅ All FOWLR gear plus:
• 🌊 Controllable powerheads/gyres to reach 20–30× in-tank flow; create random/turbulent patterns.
• 💡 Reef-capable lighting (right PAR & spread).
• 🤖 ATO is essentially essential (salinity stability).
• 🫧 Protein skimmer (practically essential beyond light bio-load).
• 🧪 Alk, Ca, Mg, PO₄ test kits; consider dosing pumps or kalkwasser as demand grows.

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3) Water Source & Mixing (salt/brackish specifics)

• 🚰 RO/DI basics: 4–5 stages (sediment → carbon → RO membrane → DI).
  🧪 Use a TDS meter: product water near 0–5 ppm. Replace DI resin when TDS rises.
• 🧂 Mixing: Use a dedicated brute can with a small pump and heater; mix 24 hours for full dissolve/temperature.
• 🔬 Measure salinity at 25°C/77°F; calibrate refractometer with 35-ppt solution (not RO water).
• 🛡️ Keep a lid on the mixing barrel to limit dust/CO₂ absorption.

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4) Flow & Gas Exchange

• 🌊 Surface ripple = oxygen. Aim a return or powerhead to gently disturb the surface.
• 🌀 Placement: create a circular flow path so debris drifts toward the intake.
• 🪸 Reef: alternate modes (lagoon, reef crest) and avoid direct blasting of corals; let polyps sway.

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5) Quarantine & Emergency Gear (highly recommended)

• 🏥 QT tank (10–20g), seeded sponge filter, heater, lid.
• 💊 Core meds on hand: ich remedy, broad-spectrum antibiotic, praziquantel/metronidazole, methylene blue, aquarium salt.
• 🛟 Ammonia-binding conditioner, extra air pump + airstone.
• 🧴 Carbon/Poly-Filter for suspected contaminants.
• 🔧 Spare impeller, O-rings, silicone grease (aquarium-safe) for seals, PTFE tape for threaded fittings.

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6) Sizing Cheat-Sheet (quick numbers)

• 🌀 Filter flow (actual):
  • 20g planted: 120–140 gph
  • 40g community: 240–280 gph
  • 75g cichlids: 600–750 gph (often two units)
  • 75g FOWLR: 450–750 gph through filter + powerheads for 10–20× in-tank
  • 75g reef: powerheads totaling 1500–2200 gph (20–30×), filtration 3–5× through sump/canister
• 🔥 Heaters:
  • 20g: 75–100 W • 40g: 150–200 W • 75g: 250–300 W
  Use two (e.g., 2×150 W on a 75g) for redundancy.
• 💡 Photoperiod:
  Fish-only 6–8 h (aesthetic) • Planted 6–8 h (tune to algae) • Reef 8–10 h (ramp if using schedules).

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7) Setup Order (commissioning checklist)

1. 🧱 Place/level stand & tank (drip loops planned, GFCI ready).
2. 🚿 Leak test tank/Plumbing (freshwater, 24 h).
3. 🪨 Rinse substrate/hardscape; aquascape.
4. 💧 Fill (fresh: dechlor; marine/brackish: RO/DI + mixed salt).
5. 🔥 Heat to target; start filtration & flow; check for micro-leaks/air.
6. 🧪 Begin cycle (ammonia source + bottled bacteria optional).
7. 💡 Add light/timer; program photoperiod.
8. 🧪 Test until NH₃/NO₂⁻ = 0; stock gradually (reef: QT fish, dip/inspect corals).
9. 🤖 Add ATO (marine/brackish; optional fresh).

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8) Maintenance Intervals (typical)

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9) “Essential vs Optional” Matrix

(✅ essential • ◻️ helpful/depends • — not needed)

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10) Common Pitfalls (and fixes)

• ⚠️ Over-cleaning filters → bio crash
  ✔️ Rinse in tank water, stagger media changes.
• ⚠️ No dechlorinator on tap water
  ✔️ Always dose; chloramine is common.
• ⚠️ Undersized flow / dead spots
  ✔️ Add powerhead/spray bar; aim for a gentle loop.
• ⚠️ Hydrometer drift (marine)
  ✔️ Use a refractometer; calibrate with 35-ppt solution.
• ⚠️ Heater stuck on
  ✔️ Dual heaters or controller + temp alarm.
• ⚠️ ATO flood
  ✔️ Use optical + float failsafe and keep reservoir below the rim height.

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🏳️ Not an end-all, be-all

This is a framework, not a final rulebook. Your species, room, and routine will change what’s “essential” for you. Start with the core, add the nice-to-haves that reduce your workload, and keep the system boringly stable.