Yitzchok Rosenberg // Kings Fish Tank and Maintenance, Inc.

hen Yitzchok Rosenberg shows up for an install, one of the most common reactions he receives is “I wasn’t expecting someone looking like you.”
The fish tank business is not a typical occupation for a chasidishe yungerman.
Some talk about turning a passion into a business, but Yitzchok actually did it. He does everything from building high-end complex and beautiful fish tanks for corporate clients to maintaining simple fish tanks in private homes.
In the US alone, over 12% of the population own indoor fish tanks, but maintaining them is the key to keeping your fish around for longer than the ones your kid won at the carnival. A core part of Yitzchok’s business is providing monthly fish tank maintenance to maintain their clean and healthy environment.
Yitzchok shares some of his tips on turning your interests into your business, and of course, on keeping your fish tank in good shape.

I was born in Borough Park to a family of Vizhnitzer chasidim. I grew up davening in the Vizhnitzer Shul on 53rd Street and 18th Avenue. I went to the yeshivah ketanah of Vizhnitz, and for yeshivah gedolah I went to Gibbers in Kiamesha Lake, which was under Vizhnitz of Monsey. Soon after yeshivah gedolah, on the day I turned 20, I got engaged, and then I went to Israel and learned in the Mir for about five months. I then returned home and got married.
I always took my learning seriously. I focused on the weekly learning quotas and made sure I knew the material. In yeshivah gedolah I used to try to learn for 11 consecutive hours once a month, which would be reported to the Rebbe, zt”l. I was focused on my learning. I didn’t get involved in other things. Kiamesha Lake is in upstate New York, so I was able to go hiking from time to time and do some other activities during breaks.
I’m the seventh in a family of 12 children. My father and his brothers own the Marcy Tires shop in Williamsburg. They’ve been in business for over 35 years. They service all types of vehicles, including trucks and buses. My father is also the founder of the Chesed Shel Emes organization and is involved in communal activism. He was also a dispatcher for Shomrim for over 30 years.
My mother worked at home. Raising 12 children is a career in itself. She helps a lot with the Chesed Shel Emes office work. She’s also involved with Yad Yaakov, which has two Bikur Cholim rooms in one of the Brooklyn hospitals.
As a child, I loved nature. I was that kid who used to go around collecting salamanders in camp. I also loved fish and used to go fishing. I used to bug my parents to get me a fish tank. Finally, when I was about 13, my father’s friend bought me one.
A fish tank comprises many parts: a heater, a filtration system, sand, lights and decorations. Once I set everything up, I had to learn how to take care of the fish. So I went to the pet stores and asked questions, got some books on the topic, and taught myself how to do it. Eventually I bought a larger tank, and then an even bigger and better one, and I experimented with different types of fish. At some point I realized that I really knew what I was doing. It was at that point that family and friends started asking me to help take care of their fish.
When my fish had more babies than I could care for, I would offer them to whoever wanted them. And then I would take care of the fish that I gave them. I never thought that this would eventually turn into a business.
When I got married and moved out of my parents’ home, I stopped maintaining my big fish tank there. One day my father called me and said, “Yitzchok, you have to come take care of the fish. They’re starting to die!” So I went over and did what I had to do. But I didn’t go over often enough to maintain it properly, so my father told me that he was going to hire a company to take care of it. When I heard that, I decided that there’s no way my father is going to do that when I can do it myself. So my father started paying me, as a joke, to incentivize me to maintain it on a regular basis.

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