The boy who has loved the water all his life now lovingly looks over his fish tank—as soon as he wakes up, when he comes home at the end of the day, and before he goes to bed. LEEHAN of BOYNEXTDOOR is father to many fish. He claims that nothing makes him happier than to see his “babies” eat, and nurtures a wonderful world of his own inside a small aquarium. LEEHAN shares his philosophy on his fishkeeping hobby, otherwise known as mulsaenghwal in Korean, and how he creates a picturesque miniature ecosystem inside his fish tank.

*물생활 (mulsaenghwal): Literally translated to “water life”; means the hobby of keeping fish

Fish, the first encounter

LEEHAN: When I was in elementary school, my parents brought home these fish called guppies. I was too young back then, so I didn’t exactly know how to keep fish. I also had a yellow cichlid that we named Banana. The little guy died because I didn’t know how to properly take care of him. I was devastated, and I buried him in my parent’s plant pot. I even made a little headstone with his name on it. I grieved for about a year and realized that I had to be more responsible and do more research if I was going to care for another living being. Starting in middle school, I started to read up on how the nitrogen cycle worked (the cycle in which waste is broken down to establish the right environment for fish to live in) and took a dive into the world of keeping fish.

The heart of the aquarium - the filter

LEEHAN: The filter is the device that circulates the water inside the tank. If the filter is powerful, the water becomes remarkably clear, and you can see the difference in how the fish behave. They’re constantly coming out with new filters, just like smart phones, and I keep Googling them because I want only the best for my fish. (laughs) There are lots of different types, like the sponge filter, and external filters. I use the external filter. It’s quieter and doesn’t take up space inside the tank. I like that it’s almost invisible if you use clear tubes for the water going in and out of the filter. I think that the filter is the heart of the aquarium, so I use one that’s way too big for my tank. Think of it as using five air conditioning units for a single room. (laughs) If you do regular water changes and have the tank properly cycled, then a normal sized filter would be enough, but I might not be able to care for my tank all the time because I might get busy and have to go overseas for a few days for pre-shootings and making music videos. I got my fish the best filtration system I could to make sure they’re kept in a healthy environment in any situation.

BOYNEXTDOOR is introduced to keeping fish

LEEHAN: I asked the members for over a month before getting my fish tank set up. I’d be like, “Are you absolutely sure?” and “Can I really have a fish tank?” every chance I got. I was persistent. They’re living beings, so if you decide to have them, you have to be responsible for them. I was hesitant because the other members might not be comfortable with it, but they were actually very supportive, so I set up my fish tank. I’m really grateful. The members showed a lot of interest when I first set up my tank. They asked what all the devices were and came to watch while I worked. But after about four months, their curiosity died down a bit, and the tank just became a part of their lives. We go on with our lives in our respective rooms. (laughs) We’re exactly like how we appear on “FUNNEXTDOOR.” We’re all happy just doing what each of us wants to do.

Feeding the fish

LEEHAN: When I feed my fish, the members come over, wanting to help. You see, the fish gather around at feeding time. But naturally, I’m almost the only one who feeds them. That’s the whole point of keeping them! (laughs) I tend to be precise when it comes to how much I feed them. If I fed them already, I tell the members to feed them the next morning. But then I end up being the only one feeding them again. (laughs) One of the guys would show up in the evening when I’m feeding them dinner, and they’d be like, “I was supposed to feed them, but I didn’t get to!” and I’d let them. (laughs) You must keep an eye on your fish when they eat. About three out of 10 don’t feed enough. They’re outcasts. Some fish feed a lot and get big and plump, but some won’t and get skinny. I remember those ones, and see if they got enough to eat.If they didn’t, I follow them around until they do.

Adorable corydoras

LEEHAN: If you spend enough time watching the fish, you’ll notice that they each have different personalities. There’s a bully that picks on his tank mates, and there’s one that’s docile who keeps to his corner, getting picked on. They’re all different even if they’re the same species. Corydoras are usually easygoing. It’s so chill, that it doesn’t even care if the other fish come and pick on it. The name comes from Greek—“kory” means helmet, and “doras” means skin. So, they’re fish with helmet-like skin. If you see their bone structure, you’ll notice that their head is covered in armor. That’s probably why they aren’t bothered when they’re attacked. They’re resilient and cute.

The coolest fish, the northern snakehead

LEEHAN: When I first started keeping fish, I liked the colorful ones, but now I gravitate towards the more muted ones. There are these foreign species of fish that are called “snakeheads” that are similar to the Korean northern snakehead fish, but their color and size are different. They’re much more eye-catching, but I like the native snakehead more. They’re the definition of resilience and strength. If you see them in person, you’ll be like, “Hello, sir” before you know it. (laughs) Korean snakeheads are incredibly powerful and magnificent. They look cool too. Their snake-like head and pattern are amazing. 

South America themed fish tank

LEEHAN: My current fish tank is South America themed. The whole aesthetic of a tank can change drastically depending on the stones, rocks, or driftwood you use. Before I used volcanic rocks, then added in what’s called “blue dragon stones,” with river sand. But this time around, I used white sand and a lot of driftwood. I used to have aquatic plants from Southeast Asia, but I took them all out and planted big sword plants that spread quickly. I think they’ll get more established in no time. I recently got angelfish and otos. Angelfish can grow these beautiful vertical fins depending on how tall your tank is. I can’t wait to see how mine turn out. But they’re troublemakers - they tend to do whatever they please. Thankfully the other guys in the tank are too fast, so we don’t have any fights breaking out. The otos are like corydoras that like to hang out on the glass. They’re adorable guys that like to eat algae.

Hobbies for fish: snorkeling, and scuba diving

LEEHAN: I love snorkeling. I’m from Busan, so I used to swim in the sea with fins on. I went scuba diving in Southeast Asia once, and it was so cool to see crayfish and whale sharks in the wild. I made lots of great memories. Going overseas is great, but I’m more into Jirisan Mountain and streams in Gangwon-do at the moment. There are pretty deep parts of the stream so you can even go snorkeling. During fall, the red leaves fall into the water turning the whole place red. There are lots of beautiful places around Korea. There are lots of pretty fish too, so I want to see them most of all. You need a license that you can get in four stages if you want to scuba dive professionally—I heard that you could go into deeper waters depending on your license. I couldn’t get a license before because I was too young, but I’d love to one day when I get some free time!

Fish-watching dog, Connie (LEEHAN’s family pet dog)

LEEHAN: I couldn’t believe it at first, but Connie likes to watch the fish. Tanks are usually very heavy, so you can’t put them on the table or other regular furniture—they’ll bend. We have these specialized stands that are built to the size of the tanks. The fish tank stand back home is pretty tall, and Connie would sit on the floor in front of it and look up. I would sometimes sit on the floor with him and watch the fish together before going to bed. I would turn off all the lights except the fish tank, and he would pitter patter over and sit with me to watch the fish. He’s so cute. (laughs)

BOY NEXT FISH

LEEHAN: RIWOO reminds me of the boxfish. It’s a saltwater fish that’s small and shaped like a ball. It’s really cute. It’s the cutest saltwater fish I’ve seen so far. (laughs) TAESAN is the blue tang. It’s the kind Dory is, the character from Finding Nemo. They’re super playful, and sleep on their sides. They sometimes play dead, and sleep stuck in weird places. I think they’re playful just like TAESAN. WOONHAK is definitely a corydoras. (laughs) WOONHAK looks for food and eats it. (laughs) He’s really chill but also caring and cute. That’s his charm. JAEHYUN is the balloon molly. They have these pouches on either side of their cheeks, so they swim the way a dog wags its tail. JAEHYUN’s like a cute puppy, so he is just like the balloon molly. SUNGHO is the zebrafish. They’re really active and sturdy. They’re one of the most resilient aquarium fish out there. They’re so resilient in fact, that they’re used to cycle the tank. They adapt well to new environments, so they’re a lot like our energizer SUNGHO who’s always full of life. Lastly, I’ll pick the snakehead for myself!

The joy of fish-watching

LEEHAN: It’s like having a small world of my own. I can make the tank look the way I want it to look, and I can watch the fish I like for as long as I please. The first thing I do when I get home is to go to my tank and greet my fish: “How are my babies?” The fish are really small, so I call them “babies” or “children.” (laughs) I check and see if they’ve been well, if any of them are sick or not, how much food is left—I keep a close eye on them. I go watch them for a while after I shower, I watch them while I eat something, I go feed them one last time before I go to bed, and make sure that everyone’s well fed. I’m constantly checking up on them. I sit in front of the tank and organize my thoughts. It’s like my personal moment for wrapping up the day.

Documenting and sharing the experience

LEEHAN: I take pictures and videos of my fish with my toy camera these days. It’s low-resolution but that’s what I like about it! I’ve been posting pictures of fish along with my pictures since our debut, and I realized that I should be careful to maintain a good balance. If I post too many pictures of fish, then there would be a wash of comments saying that they want to see more pictures of me. (laughs) But my fish are so pretty to me which makes me want to share them. It’s good to share what you love, you know? I’ve been sticking to a schedule so that I can show ONEDOOR what I want to show them and what they want to see. (laughs)

A message for the fish

LEEHAN: I want to ask them if they’re happy. I’ve gotten them a bigger tank, but I’m still curious if they have enough space, and if they’re happy. I also want to know what their favorite food is—there are many different types. I don’t talk to them too often, but I want to thank them for eating their food without making a fuss, and that I hope they keep eating the way they do. I think I’m happiest when my fish are well fed. They’re the cutest and loveliest when they eat.