Sometimes size really does matter. Truly devoted aquascapers want to go big or go home, pulling out all of the stops to create a massive home aquascape that rivals their local public aquarium. Ready to be blown away by some of the largest personal aquariums in the world? You might want to put on a snorkel.

3. Jack Heathcote’s Cellar Aquarium

I covered Jack Heathcote and his gigantic room-sized aquarium a few months ago, but he still deserves to make the list. This fish fanatic’s 12 ft. x 12 ft. x 7 ft. aquarium, which is located in Heathcote’s cellar, is as large as the room above it.

Jack Heathcote's Home Aquarium

Image source: Dailymail.co.uk

Maintenance in such an enormous aquarium is no small task. Every week, Heathcote has to don his swimming suit and dive underwater to scrub off algae and perform tank maintenance for his grateful fishy buddies.

2. John Marcus’ Monstrous 10,000 Gallon Aquarium

John Marcus of Los Angeles doesn’t park cars in his garage — nope, he uses it to house his positively gigantic home aquarium. This bad boy is so huge that it makes Heathcote’s 4,800 gallon aquarium look like a fish bowl by comparison. In fact, Marcus estimates that his 26 ft. x 12 ft., 10,000 gallon aquarium is the largest private home aquascape in the world.

But don’t take my word for it. I’ll let video footage of this Godzilla-sized tank speak for itself.

1. Okeanos Aquascaping Backyard Aquarium

Wait a second… if John Marcus’ aquarium is the largest home aquascape on Earth, then why isn’t it in the number one slot? Well, as ambitious as Marcus’ aquarium is, it just can’t hold a candle to the truly visionary backyard custom aquarium swimming pool. This enormous, 50,000 gallon L-shaped aquarium is 30 feet wide, 60 feet wide, and a staggering 25 feet deep (that’s as tall as most two-story houses). As if that wasn’t already jaw-dropping enough, the aquarium sits next to a luxury swimming pool. Residents will be able to swim alongside sharks, stingrays, and other aquatic beasts without worrying about losing a leg to a hungry man-eater.

Okeanos Aquascaping's Ultimate Backyard Custom Aquarium

Image source: Okeanosgroup.com

The only catch? It hasn’t been built yet. This aquarium of aquariums can be yours for the low price of $11 million.