Page 3 - Saltwater Aquarium Beginner’s Guide | How to Start a Saltwater Tank Step-by-Step

What do I need to start a saltwater aquarium?
To begin a saltwater aquarium, you’ll need:

• High-quality glass or acrylic All-In-One Aquarium is best choice for beginners because filtration is built right into the tank.
• Aquarium heater
• Salt mix
• Powerhead for internal water flow
• Refractometer to measure salinity
• RO/DI system to purify tap water and mix your own saltwater
• Test kits to monitor water quality and maintain water chemistry
• Reef-capable LED lighting to support coral growth

• Protein Skimmer
• Auto Top Off System
• Aquarium Controller

Is a saltwater aquarium hard for beginners?
Saltwater aquariums can feel complex at first, but modern equipment and proven techniques make it easier than ever to achieve long term success. In fact, modern saltwater aquariums are right on PAR with any traditional freshwater tropical fish aquarium in terms of maintenance and level of upkeep. Additionally, the widespread availability of sustainable, captive-bred marine fish & corals is growing every year, with new species becoming available to hobbyists all the time. The most important part is taking things step-by-step. This guide provides clear direction on cycling, stocking, feeding, and stable water chemistry, helping new hobbyists avoid common mistakes and enjoy a thriving tank.

How long does it take to cycle a saltwater tank?
The cycling process typically takes 2–4 weeks, but can vary depending on your biological filtration and the bacteria source you use. Bottled nitrifying bacteria can reduce cycling time. You’ll know the cycle is complete when ammonia and nitrite reach zero and nitrate begins to appear. Only then is it safe to begin adding livestock.

What are the best beginner saltwater fish?
We always recommend that you source captive-bred fish because they are much hardier than wild-collected fish. Look for small, peaceful community fish that won't break the bank and won't cause trouble with aggression toward tankmates.

• Clownfish
• Gobies
• Damsels
• Dottybacks
• Learn More: Top 20 Beginner Fish For Saltwater Aquariums

How big should my first saltwater aquarium be?
A 20–40 gallon tank is usually the easiest size range for beginners. Larger water volume provides more stability, making it easier to maintain consistent salinity and water chemistry. Smaller nano tanks can be successful but require more careful monitoring.

Do I need live rock and live sand to start a reef tank?
Live rock and sand supply beneficial bacteria and micro-organisms that support biological filtration and nutrient processing. While you can start with dry rock and add bacteria supplements, including some live rock can help seed the system more quickly and improve biodiversity.

What is the difference between fish-only and reef aquariums?
A fish-only saltwater aquarium focuses on marine fish without corals. A reef tank includes corals and sometimes other invertebrates like snails, shrimp, or starfish. Reef tanks require more specialized lighting and stable calcium, alkalinity, and trace elements to support coral growth.

How often should I test water in a new saltwater tank?
During cycling, you should test every 2–3 days to track ammonia, nitrite, and nitrate. Once livestock is added, weekly testing helps ensure parameters remain stable. Testing becomes less frequent over time as the tank matures and you establish a regular maintenance routine.

How much does a beginner saltwater aquarium cost?
A simple starter setup with beginner-friendly fish typically ranges from $300–$1,000 depending on the size of the tank and quality of equipment. Investing in reliable gear early on helps prevent costly issues later.

What type of lighting do I need for corals?
Corals need full-spectrum reef lighting with a heavy UV - Blue spectrum designed to support photosynthesis. LED reef lights are the most popular option due to their efficiency and controllability. The type of light you choose depends on your tank's dimensions and the coral species you plan to keep.