How Much Does a Custom Aquarium Really Cost?

It's the first question everyone asks, and the honest answer is: it depends on what you're building. But after 20+ years and 300+ service accounts, I can give you real numbers not the vague "call for a quote" runaround

The quick rule of thumb

A fully stocked reef system with quality cabinetry generally runs $100–$125 per gallon. So a 120-gallon showpiece lands around $12,000–$15,000 all in. Freshwater and fish-only systems cost less sometimes substantially because the lighting and life-support demands are simpler.

Custom projects with Fish Doctor start around $5,000. From there, systems range from 50 gallons all the way past 5,000.

Where the money actually goes

A custom aquarium isn't just a glass box. Here's what you're paying for:

- The tank itself. I work primarily with Planet Aquariums excellent build quality, and sized exactly to your space. Odd dimensions, room dividers, in-wall installations: this is where "custom" starts.

Life support is the Filtration, protein skimmers, pumps, heaters, controllers. This is the engine room, and it's the difference between a tank that thrives and one that fights you every week. Buy it right once or buy it twice.

Lighting is Reef lighting feeds corals that are photosynthetic animals, and cheap lights grow algae, not coral.

Cabinetry and stand are the furniture under and around the aquarium. Furniture grade cabinetry that matches your home, built to hold thousands of pounds of water without a wobble.

Installation includes the Delivery, placement, plumbing, leak-testing, cycling. A 300-gallon system weighs over a ton full — this is not a DIY afternoon.

Livestock are the animals, the fish, corals, invertebrates quarantined and sustainably sourced. I stock captive-bred animals wherever possible, including ORA and Ocean Rider Farm livestock.

What about after it's built?

You need to budget for maintenance. Professional service for systems up to 300 gallons generally runs $300–$600 per month water changes, equipment checks, water chemistry, livestock health. Every custom build from Fish Doctor includes two months of scheduled maintenance so your system starts stable and stays that way.

The free part

Here's what costs nothing: my on-site consultation. I'll come look at your space, talk through what you want, and give you a straight number no pressure, no obligation. If a custom build isn't right for you, I'll tell you that too.

Twenty five years in, I'd rather talk you out of the wrong tank than sell you the wrong one.

Call or text (650) 922-7744 for a free on-site consultation.