Fish are allowed in most apartments, but whether fish are allowed in your apartment depends on what your lease says, what your landlord approves, and how large a tank you want to keep. A small desktop tank rarely raises objections. A 75-gallon setup that weighs several hundred pounds is a different conversation, and one you need to have before you buy anything.
What Your Lease Says About Fish
The lease is where this question gets answered. Some leases mention aquariums by name and set a gallon limit. Others use broad language like “no pets” or “no animals” without saying whether fish count. A few leases say nothing at all about pets.
A blanket “no pets” clause technically covers fish unless the lease carves out an exception. Silence doesn’t mean permission either. If the lease doesn’t address pets or aquariums, get written approval from your landlord before setting up a tank. Assuming silence equals consent is the mistake that leads to disputes later.
Even leases that permit fish often cap tank size. Reported limits range anywhere from 10 to 55 gallons depending on the building. Look also for clauses about waterbeds or large liquid containers, since landlords sometimes use those provisions to regulate aquariums indirectly.
Why Landlords Restrict Aquariums
Landlords who allow dogs and cats sometimes ban large tanks, and landlords who prohibit all other pets sometimes allow fish. The logic isn’t about the animal. It’s about risk.
Fish don’t bark, shed, or trigger allergies. What they do is sit in one place, heavy and full of water, for years. Landlords who restrict them are almost always thinking about two things: sustained structural load and the possibility of catastrophic water damage from a leak, cracked seal, or equipment failure. Understanding that framing helps when you’re making a case for approval.
Landlords who allow fish often attach conditions. Common ones include a maximum tank size, ground-floor placement, a drip tray or waterproof mat, or a pet deposit earmarked for potential water damage. These conditions are often negotiable if you come prepared.
Tank Weight and Floor Load
Water weighs about 8.34 pounds per gallon at room temperature.1WorldAtlas. How Much Does A Gallon Of Water Weigh Add glass, substrate, rock, and equipment and the weight climbs quickly. A fully set up 10-gallon tank runs about 100 to 110 pounds. A 50-gallon tank runs 500 to 540 pounds. A 100-gallon tank approaches 1,000 pounds.
Residential floors in the United States are typically engineered to support 40 pounds per square foot in living areas and 30 pounds per square foot in bedrooms. Those ratings assume transient loads: people walking, furniture being moved. An aquarium is stationary and permanent, which stresses wood framing differently over time. For a sustained load, the effective capacity is roughly 10 percent lower than the live-load rating.
In practice, a 55-gallon tank on a standard stand concentrates around 550 pounds onto roughly four square feet, producing a load near 135 pounds per square foot. That exceeds the rated capacity of most residential floors by a factor of three. Placing the tank against a load-bearing wall or directly over a floor joist helps distribute the weight, but a large tank on an upper floor is a real structural concern, especially in older buildings that predate modern codes. This is the single biggest reason landlords restrict tank size.
Water Damage and Renter’s Insurance
A failed seal, a cracked tank, or a malfunctioning filter can release dozens or hundreds of gallons in minutes. In an upper-floor unit, that water flows into the apartment below, damaging flooring, drywall, and belongings that didn’t belong to you.
Standard renter’s insurance generally covers water damage resulting from a sudden aquarium failure. That word “resulting” matters. Your policy will typically pay for damaged flooring, walls, and belongings, but not for the tank itself or the fish. Liability coverage can also apply if your aquarium damages a neighbor’s unit, though proving negligence in a sudden equipment failure is difficult. Ignoring a slow leak is a different situation.
Before setting up a tank, call your carrier and confirm in writing that aquarium-related water damage is covered under your specific policy. Coverage varies by carrier and state, and assumptions here can be expensive. Some landlords require proof of renter’s insurance as a condition of allowing a tank, which is reasonable from both sides.
Getting Landlord Approval in Writing
If your lease is ambiguous or says no pets, talk to your landlord before you bring a tank home. Landlords are far more receptive to tenants who approach the question proactively than to tenants caught with an unauthorized aquarium.
When you make your case, cover the specifics that matter to a landlord:
- The gallon capacity and total estimated filled weight of the tank.
- Where you plan to put it: ground floor, against a load-bearing wall, over a joist if you can identify one.
- Protective measures like drip trays, waterproof mats, and regular equipment checks.
- Proof that your renter’s insurance covers water damage, or a commitment to add it.
Get the approval in writing. An email works. A verbal “sure, that’s fine” has no value when you’re facing a notice six months later from a property manager who never heard about the conversation. If the landlord wants a pet deposit or additional monthly rent for the tank, negotiate the amount rather than refusing outright. A modest deposit is cheap insurance against a lease dispute.
Fish as Emotional Support Animals
The Fair Housing Act requires housing providers to grant reasonable accommodations that a person with a disability needs to use and enjoy their home.2Office of the Law Revision Counsel. United States Code Title 42 – 3604 An assistance animal under this law is not a pet, and the law does not limit which species can qualify.3U.S. Department of Housing and Urban Development (HUD). Assistance Animals
A fish can therefore serve as an emotional support animal if a licensed healthcare provider documents that it alleviates symptoms of a recognized disability. When an ESA request is approved, the landlord must waive pet restrictions, pet deposits, and pet rent for that animal.3U.S. Department of Housing and Urban Development (HUD). Assistance Animals You remain financially responsible for any damage the animal causes beyond normal wear and tear.
To request the accommodation, you typically provide a letter from a licensed mental health professional or physician stating that you have a disability and that the animal is part of your treatment. The landlord may ask for this documentation but cannot ask about the nature of your disability or demand detailed medical records. Denying a legitimate ESA request may violate federal fair housing law.2Office of the Law Revision Counsel. United States Code Title 42 – 3604
Consequences of an Unauthorized Tank
Keeping fish when your lease prohibits them is a lease violation. The typical first step is a written notice giving you a set number of days to cure the violation. These cure-or-quit periods vary by state but commonly fall between 7 and 30 days. You can remove the tank, try to negotiate approval, or ignore the notice and face eviction proceedings.
Short of eviction, a landlord can impose fines if the lease provides for them, demand immediate removal, or keep your pet deposit. Some landlords simply decline to renew at the end of the term, which achieves the same result without going to court. An eviction filing becomes part of your rental history and makes the next apartment harder to find.
If an unauthorized aquarium causes damage, the financial exposure grows. A landlord can sue for repair costs, and your renter’s insurance may not cover damage arising from a lease violation. Some policies exclude damage from unauthorized activities, which can leave you personally liable for repairs to your unit and to any neighboring units the water reached.