Ok, so a friend of mine thought it would be funny to toss seeds into my pirahna tank. The next day i noticed one stuck to my filter had sprouted. Now three days later it's grown about 2.5 inches. I really don't know much about growing, but the tank is heated, gets plenty of light, and i'm assuming nutrients from the fish.

Is there anything i'm missing or can i just let it grow?

Look up aquaponics. The fish will eat the plant sooner or later.

Hoppin, I'm pretty sure piranhas don't eat plants. My friend who grows (the best bud I have ever smoked) cleans out his fish tank and uses all the crap for fertilizer. I'd say let it grow and see what happens, could be interesting.

lets get some pics.

I have had the same experience. I used to throw beaners in my fish tank and they would actually grow. Seems to me the water all filled with fish poop would make a good fertilizer. Mine never got bigger than 3 to 5 inches though.

Like I said look up aquaponics. Its Hydroponics that use fish and other water creatures to create a eco-system for the fish and plants. And allows you to use the fish water to supply nutes to the plants and the plants take the waste products that supply them nutes and clean the water and add more oxygen to the water. I was real into it a few years ago and had a large fishtank that would pump into an ebb and flow hydroponics system on a timer. The fish tank has to be large if you are doing this method because It takes water away from the tank for a few minutes.

Overgrow had some sweet pot aquaponic setups, I bet you can still find them on google on some of the other grow sites.

It's a 25 or 30 gallon tank so it should be plenty big enough, and i only have one piranha left. I looked into aquaponics It should work pretty good, I was wondering more about what i would have to do to care for the plant.

yeah, when you finish growing it cure it properly. You michigan fucktards never cure the bud right.