Can floating islands lose their bouyancy

[Arey]

This picture is from May of 2011. Each year I would plant two compact papyrus in each island, and this year they've been a mess. With two compact papyrus plants in each island, the top surface of the islands were a bit beneath the water surface. I whacked out half of each of the plants and removed some of the planting material (Yes, they look like the dickens) but they are both very low in the water, and one is almost half submerged. Is there anything I can do to restore the bouyancy, or should I just buy new islands next Spring?

I also have an algae question. In a recent post I read that you can kill algae on a waterfall by spraying it with peroxide. Does that mean I can put the peroxide in a spritzer like people use for spraying their seedlings, and convincing their cat that countertops are not suitable for foot traffic. What is the best time for spraying? And would I use straight peroxide or would I need to dilute it?

 

[Mmathis]

Is water getting inside the closed plastic? Other than just the accumulated weight of the plants & substrate, can't think of anything -- when you "whacked" them up, did you pull them and trim back roots, or did you only trim the plants above-water level?

I have some floating planter rings that keep my water lilies suspended (Addy's idea). I have to work hard with buoyancy issues, as these rings do need to be just below the surface. But noticed last winter than when the water cooled, the rings with plants sank. Then as the water warmed this spring, they floated back up.

 

[Arey]

The black plastic planters come with four holes in the bottom that fit inside the floating ring. This way the plants are above the water level, but the planting medium is saturated and the plant roots can go down into the pond water. When whacking, I took each planter out of the ring and cut the plant in half and discarded half. I was wondering if, over the years, the plastic floating ring could lose its bouyancy from being clogged with hair roots, algae, and such. Also if the weight of the full planter could compress the floating ring somewhat.

I did see advertised a special light weight planting materialfor use in floating islands, and was wondering if this was the solution. Right now I use aquatic plant planting material which turns into what looks like brown clay, and I cover the surface with pea gravel.

 

[sissy]

The ring is the foam that is dense .I just spray under them with a little spray foam in a can .I have the smaller ones but I did not put them in this year ,just no time to be bothered with them .The peroxide on the water fall rocks works best with heat or sun as they both make it work faster .I use one of those miracle grow hand pump sprayers .I bout one just for that and it is marked also clearly .