FISA--when I was trying riccia, I used some plant weights that looked like heavy wire that came on an order from lowcoaster. They worked really well for small patches. I see in another post (swap-n-shop section post on plant weights), that he sells the weights separately on aquabid. If they come precut to the size I got, they will work well for small patches (say 1"X 2"). If they come in a roll where you cut them yourself, then you'd be able to make whatever size you want.