We're going away for two weeks, so I just did a thorough cleaning of my 65, including both filters. When I replaced the marimo mossballs after vacumming the substrate, they all sank to the gravel and are sitting there as usual -- except for one, which is now floating at the surface, riding the current, and doesn't act like it's going to drop down anytime soon. It's a really fat, dark green one.
Why would this one mossball float while the others all sank, and how do I get it to sink, also? It was down with the rest of them before I cleaned the tank, and just now started floating. This is the first time I've ever had a mossball float. Many of those which sank are just as big and fat as this one, but for some reason, this one got lighter in weight than the others and no longer stays down.
20 gal. high: planted; 1 zebra danio, 6 glofish, several snails, 2 (visible) RCS; AC50, Azoo air. 65 gal: planted; 4 rosy barbs, 6 glofish, 5 white cloud minnows, 3 zebra danios, 5 dojo loaches, several snails; AC110 x 2.