💧 Automatic Water Change System for Multiple Aquariums

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🏗️ Core Components You’ll Need

🔹 Freshwater Supply Line 🚰

• From tap (with chlorine/chloramine filter) or an RO/DI system.
• Use PEX, PVC, or polyethylene tubing (¼"–½") to carry water.
• Add pressure regulator if water pressure is too high (>60 PSI).

🔹 Distribution Manifold 🔧

• A main PVC/PEX line running across your tanks.
• Branches into individual valves (ball valves or drip emitters).
• Allows you to fine-tune flow for each aquarium.

🔹 Float Valves (Auto Shut-Off) 🛑

• Installed in each tank to prevent overflow.
• Options: mechanical floats (like toilet valves) or optical/electronic ATO sensors.

🔹 Drainage System 🕳️

• Drilled bulkheads & standpipes OR PVC siphon overflows.
• Connect all tanks to a central 1.5–2" PVC drain pipe → floor drain, laundry tub, or sump pit.

🔹 Automation Add-Ons ⚡

• Solenoid valves connected to a timer → controls water flow.
• Flow restrictors or drip emitters → keep system balanced.
• Check valves → prevent back-siphoning.

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🛠️ Step-By-Step Setup

1️⃣ Freshwater Input 🚰

1. Run a main line from your water source (tap, RO/DI, storage barrel).
2. Add:
   • 🧴 Sediment & carbon filter → removes chlorine/chloramine.
   • 💊 Optional auto-dosing pump (like a peristaltic pump with Prime or Safe) if you prefer chemical dechlorination.
   • ⚡ Booster pump for RO/DI units if needed.

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2️⃣ Distribution Header Line 🔧

1. Install a PVC/PEX pipe horizontally above or behind your tanks.
2. Add tee fittings with small shutoff valves for each tank.
3. Connect ¼" tubing → run directly to each aquarium.
4. Attach tubing to float valve or drip emitter inside tank.

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3️⃣ Tank Fill System 🐠

• Float Valve Method
  • Each tank gets a float valve that opens/closes automatically.
  • Example: Hudson Valve (for big tanks) or small ATO float valves.
• Drip Emitter Method
  • A slow, continuous drip enters tanks (balanced by drainage).

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4️⃣ Drain System 💦

1. Drill each tank OR use PVC “U-Tube” overflows.
2. Place standpipes at your desired water level.
3. Connect all drains into a main PVC line (sloped slightly downward).
4. Route main line → floor drain, utility sink, sump pit, or outdoor outlet.

⚠️ Always include a trap/air gap to prevent sewer gas or backflow.

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5️⃣ Automation & Scheduling ⏱️

• Continuous Drip (simple, reliable)
  • Water drips 24/7 into tanks.
  • Old water overflows → drain line.
• Timed Fill (solenoid + float valves)
  • Solenoid valve opens via digital timer (e.g., 1 hour daily).
  • Fills tanks until floats shut water off.
• Hybrid Setup
  • Drip for stability + timed flushes for extra refresh.

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⚙️ System Configurations

🔹 Continuous Drip System 💧

✅ Pros: Simple, stable water quality, little risk of overflow.
❌ Cons: Uses more water, slower for large fish rooms.

🔹 Batch Fill with Timer + Float ⏱️

✅ Pros: More controlled, less waste.
❌ Cons: More moving parts → floats/timers can fail.

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💵 Estimated Costs

• PVC/PEX pipe & fittings → $50–100
• Float valves (per tank) → $8–15 each
• Filters (sediment + carbon) → $50
• Solenoid valve + timer → $40–60
• Drain plumbing → $50–150
  ➡️ Typical multi-tank setup: $200–400 depending on size.

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🌟 Pro Tips for Success

• 🧯 Always keep a manual shutoff valve on the main line.
• 🧪 Test chlorine/chloramine removal before trusting system.
• 🛠️ Build modular → unions in PVC make repairs easy.
• 🐟 Start with 1–2 tanks, then expand once proven.
• ⚡ Add a Wi-Fi leak detector near the drain for extra safety.