Cat Got Your Tank?

Read Time: 6 minutes

7 Tips and Tricks for Keeping an Aquarium with a Cat

The only cat rival as iconic as the mouse is the fish. 

Can you keep a fish tank with a cat? Absolutely. You just have to outsmart the cat first (sometimes easier said than done) and understand a little bit about cat behavior. 

Cats are obligate carnivores: they have to have meat and protein to thrive. Though hunting instincts differ from cat to cat, they all share a relatively strong prey drive that causes them to chase and track down food (even if they already have food in their bowls). This can look like stalking a speck on the wall with those big cat eyes, going crazy for a laser pointer...or making your fish miserable by pawing at the tank glass. Very cute to us, a bit like Jurassic Park to your fish. You want your cat to engage in these healthy behaviors, but you also don't want your fish stressed out from constantly seeing a predator. 

It's important to distinguish your cat isn't misbehaving or doing this maliciously; he's following his survival instincts. He's trying to secure food for himself (and maybe for you, too, if you have a cat who likes to bring you "gifts"). How'd you like it if someone nailed you with a spray bottle next time you went to pick up pizza rolls?

So, how do you overcome this drive and keep your cat and your fish happy at the same time? We'll help you out (And yes, my cat, Zoe the fishtank fiend, will make an appearance).

Tip 1: Secure Your Tank/Equipment

Keeping your tank on a secure surface and managing your cords is important even if you don't have a cat, but a cat makes it even more crucial. Cats sometimes like to play with cords since they look like string and can get caught on/unplug cords when they're doing their routine 3AM zoom around the house for no reason. Bundle excess cords together and strap them down as you can. Duct cord covers are great. If you have a tank stand, you can also mount some of the cords and power strips to it. Some hobbyists use command strips to secure cords and strips to the sides/backs of their tanks. If you have a chronic wire chewer, you can also get cord wraps or coat them in something like a no-chew bandage wrap or other substances cat taste buds find offensive. 

As far as securing the tank goes, make sure it's on a steady surface, especially if it's more top-heavy like a tall/vertical aquarium. Fish tank stands made for your tank size are good options. There are also some very cool designs with tanks in shelf nooks and entertainment systems; these can help with your cat and look nice but can also limit your access for maintenance/feeding, so do some cost-benefit analysis and choose the best fit for you. 

Tip 2: Put a Lid on It and Use Deterrents

There are some gorgeous lidless setups out there. But with a cat in the house, keeping those is asking for trouble. One of the simplest ways to protect your tank, especially if your cat can access the top of it, is to buy a hard lid. You can also use clips to secure the lid even further or place items on top of the tank to keep your cat from jumping on it. 

Some people have also had success with putting foil on top of the lids to deter cats. A lot of cats are clever and just get used to the foil, but it's worth a shot. 

Tip 3: Secure the Food - All of It

This is one I'm telling you from experience. I thought I had it all handled and figured out. I had all the cables secured, the tank wasn't accessible from any angle, my cat's stuff was far away from the tank. She could watch the fish but couldn't reach them to stress them out. I was all set.

Then, she found the algae wafers. This cat has gone absolutely feral trying to get to fish flakes before, so those were put away. But I didn't think she'd go for the plant-based stuff up on the shelf until the sound of ripping plastic woke me up at 2AM. I found her purring proudly next to a shredded (and now empty) bag of algae wafers. My herbivorous fish cried out in despair. At 2:15AM I was met with a delightfully aromatic mix of tuna-flavored cat food and algae vomit on the only carpeted surface in the apartment. 

The morning after the algae incident - she was very pleased with herself

So in short: secure any and ALL food where your cats can't get to it, even if you think they won't go for it. If they can't smell a food source near the tank, it can help keep them away from your fish, too. If you don't have a cabinet or something like that to keep the food in, you can do what I did and keep it in a plastic bin the cat can't chew through (she did try). 

Additionally, many fish foods contain garlic to aid in growth, food digestibility, parasite protection, etc. Plants from the Allium family (garlic, chives, onions, leeks, etc) are toxic to cats, so you definitely don't want to give them access to it. 

Tip 4: Pick a Good Location

Just choosing a good location for your tank can solve problems before they start. Is there a place where you cat doesn't hang out very often? Is there a part of the house that's closed off? Is there a higher area for a smaller tank where your cat can see and watch the fish but can't reach them? 

If you can't put your tank in a room that can be closed off, try to place it away from other furniture your cat can use as a stepping stone or a launch pad. DON'T do what I did in the video below with a newer tank setup back when I first started with tanks. I had to start keeping things on top of the tank to prevent Zoe from jumping on it because I couldn't move it somewhere else. Was in the middle of the first water change, she finally discovered the fish...and promptly started using the desk as a stepladder to watch her fish TV every day. 

Try to place the tank somewhere away from your cat's food, litter, and other belongings to limit their traffic around it. Having the tank in a corner or against a wall can help limit access to at least one side of it, as well. 

Tip 5: Pick the Right Plants

This might seem like weird advice for a planted fish tank. If the plants are below the water surface in the substrate, why is this an issue? The cat isn't going to access them. For most aquarium plant species, this is true. However, if you do an aquaponics setup or keep plants that have to be grown out of the top of your tank, you want to make sure your cat either 100% can't access them or that the plants aren't toxic to cats. Some of the most popular out-of-water aquarium plants are pothos varieties, and pothos (AKA Devil's Ivy, Epipremnum aureum) is a well-known toxic plant for felines. 

Some variegated pothos plants: very cool-looking, very not cool for your cat

Tip 6: Look at Water Flow

There are countless viral videos of cats falling into bathtubs or sticking their heads under running water. Funny as they are, there's a reason for it. Most cats are naturally attracted to the sound of running water. So a sink, a shower...or a fish tank filter... can make a cat trot over to check it out.

Though more research is needed on exactly why, the prevailing theory is that cats prefer to drink from running water in the wild because it's less likely to be contaminated than stagnant water. They see running water as fresher and safer than the still water in their bowl. Of course, some cats also just love to play with everything and want to bat at the water stream. 

You can approach this in a few ways. You can get a filter type that doesn't create the water flow on the surface or raise your water level to lessen it (just make sure you don't raise it too much). You can also place a sponge below the water coming back into the tank to muffle the sound - just make sure if you use a sponge you're watching it for excess bacteria, mildew, algae, etc. Some folks have also used homemade, clear, plastic chutes for the bottom of their filter that deposit the filtered water closer to the surface and lower the noise (they used cleaned out plastic soda bottles). 

If you like to spoil your cats, you can also get them a cat fountain for some flowing water that isn't from your fish tank. These aren't too expensive and might keep your cat from being tempted by the filter flow since it's more easily accessed. 

A cat drinking fountain - there are tons of other designs

Tip 7: Engage Your Cat in Other Ways

I mentioned prey drive up in the intro. One good way to prevent cats from going after your fish is to engage that drive with other activities and toys. Play has tons of benefits for both you and your cat, and if you have fish, for their sanity as well.  Providing plenty of toys, play, and attention gives your cat exercise and stimulation to help "use up" some of that drive. It's healthier for everyone. 

If your cat really loves watching fish, there are also YouTube videos made specifically for cats with fish, birds, mice, etc. you can use instead (Yes, I have set up a mini watch party for my cat before and no, I don't think that's weird). 

Keeping cats with fish can feel like you're battling nature, but it doesn't have to be...cat-astrophic. Even just a few small changes can make your life easier and let you keep both your fish and your cats stress-free. 

Got ideas? Questions? Hit us up with more blog post topics and we'll add them to the "to-write" list. Tank on!