I know you didn't ask for make shift items, but since Betty suggested the rubberband idea, I figured I would throw this one out there. The other day, I didn't feel like going on a hint for veggie clips, so I used a bamboo kabob skewer. It was perfect in my tank because my 20L isn't so deep that the whole thing was submerged, even with the pointy end shoved into the substrate for support. So, I didn't even have to get my hands wet putting it in or removing it. I happen to have a huge box full of skewers since my hubby likes to bbq.