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Saltwater Aquarium

Reef Aquarium (Mixed)

A saltwater aquarium supporting soft corals, LPS, and select SPS along with reef-safe fish - the pinnacle of the aquarium hobby.

Difficulty: Advanced Tank Size: 30g+ Recommended: 90g Budget: $2,000-$20,000 Setup Time: 90 days

📖 Overview

A reef tank recreates a slice of the coral ecosystem in your home. It's the most technically demanding and rewarding aquarium discipline - and no longer as intimidating as it once was. Modern LEDs, controllers, and reef additives have made mixed reefs achievable for dedicated intermediate hobbyists.

💧 Essential Parameters

Temperature: 76-80 F. Salinity: 1.025-1.026 SG (35 ppt). pH: 8.1-8.4. Alkalinity: 8-11 dKH. Calcium: 400-450 ppm. Magnesium: 1250-1350 ppm. Nitrate: 1-10 ppm. Phosphate: 0.02-0.1 ppm.

⚙️ Key Equipment

Sump with protein skimmer, return pump, refugium. Reef-grade LEDs with full spectrum and adjustable PAR. Wavemakers for turbulent flow. Auto top-off (ATO). RODI water filter. Test kits (alk, Ca, Mg, NO3, PO4). Doser or two-part additive system.

🔄 Cycling Process

Dry-rock cycle (3-4 weeks with ammonia dosing) or live-rock cycle (2-6 weeks). Wait for algae stages to pass (diatom, green algae, cyano) before adding corals.

🐟 Stocking Recommendations

Reef-safe fish: clownfish, chromis, cardinalfish, tangs (with size limits), gobies, wrasses (many reef-safe species), firefish. Corals: zoanthids, mushrooms, leathers (soft); frogspawn, hammer, torch, chalice (LPS); montipora, birdsnest, acropora (SPS - advanced).

⚠️ Common Mistakes

Rushing the cycle. Adding SPS corals before parameters are stable. Underskimming. Forgetting to top off evaporation with RODI (salinity rises fast). Buying incompatible fish that eat corals.