Bought a moss ball. What the heck do I do with it?

It's actually supposed to sink.

It doesn't *do* much, it's just a (primitive) plant that sits on the bottom of the tank and, if all goes well, grows.

And yes, you can cut the string and attach it to driftwood or rocks.

The correct order to do things in, which most people don't follow, is:

1. Ask "What the heck do I do with it?", then

2. Buy it.

Not the other way around.

Thats not not a real marimo moss ball, that is java moss wrapped around a rubber ball or ping pong ball and its not likely to sink. You can let it float, its healthy. Thought java moss or christmas moss, water it might be is hardy, i always manage to kill it pretty fast. As long as it is nice and green it is healthy, but remove browning peices on sight. Real Marimo moss balls, which you can get on ebay for great prices! Are really cool, they use up nutriants that other algae needs to grow, so you have a least slightly leass alga depending on how many marimos you have, "I had 30 golf ball size marimos in my 55 gallon at one point. They grow reallly slow, but when the get to like tennis ball size they start to hollow out and all of mine died after that. took several years for then to get that big though! And they are ways to save them if you know what you are doing.

It should eventually just sink to the bottom once the air is out but you can also just attach it to a rock/driftwood/whatever you want. It just chills haha. It filters out things from your aquarium and really helps with the quality of the water.

You dont have to do anything with it, thats why there so great, they will just live and live and well, live. They are great for your tank, and if you have shrimp even better..

I wouldnt glue anything in the tank, even tank safe glue.. I just dont trust it, you can safely use thread or as you already have fishing line...

I believe it gives off oxygen and what Amelia said it cleans and filters the tank