I use under gravel filter interlocking pieces under anything that I want to prevent from floating. Attach with couple zip ties where it cant be seen or effect fish. Then place gravel or sand over it to hold down. Make it so I can use rock if I am doing a natural hardscape. I have bought many things for turtles etc that I had to hold down like this. It gives me more options and it's cheaper to buy for reptiles. Its like buying baby pics at Sears. You have to hold them while not being seen in the pictures. Got to get creative sometimes. I enjoy setting up new tanks in my fish rooms. Best of luck. I'm getting one of these yet today and will most likely use one of my methods I use to be sure it dont float at any time. Best of luck and stay fishy.

Hi ZiggyBetta, Baby Shrimp would potentially use this, but larger shrimp would do best with live plants to hide in. Thanks,

Hi The dude with a question This is best for fry fish, tadpoles are generally larger than fry. Thanks,