Let me start by saying these Zelerdo feeding rings are a decent budget option if you're looking to contain floating fish food or plants. I've been using them in my 20-gallon community tank for about a month now, and here's the real tea.

The good stuff first: The square design (about 4 inches across) actually works better than round ones I've tried - food stays contained instead of swirling out the sides. The black color blends nicely with my tank background too. When they stay suctioned (more on that later), they do keep flakes from getting sucked into the filter.

Now the not-so-great: That suction cup situation? Yeah, it's hit or miss. Two of mine held strong for weeks while the others would randomly detach overnight. Pro tip: Really scrub your glass where you're placing them and let them dry completely before sticking. Also noticed some white residue when I moved one - might be leaching something, so keep an eye on water quality.

For floating plants? Meh. My water lettuce started looking sad after a few days in these. They do block light more than traditional plant corrals. Better for temporary containment than long-term plant housing.

Final verdict? At this price point, they're worth trying if you need basic food containment, but don't expect miracle suction power or plant-growing capabilities. I'll keep using mine for feeding time but won't trust them with my prized floaters!