Unidentified white Fuzz in freshwater planted tank. That moves!
My tank has been running for well over six months now. It is home to one
small freshwater clam, ten black crystal bee shrimp, and two Otos. I have it
planted with sedge, dwarf hair grass and dwarf baby tears. A few days ago I
noticed Hydra beginning on one side of the tank, they spend their time
eating the Cyclops that live in my tank as well. I've also been noticing
this white fuzzy like algae growing on my plants. It doesn't seem to harm my
plants in any way but it slowly covers the plant. I spent some time staring
at it yesterday and moved my planting tweezers to touch it, and all of it on
the plant I touched, retracted. After a few seconds it slowly came back out.
I have no idea what it is. It's not hydra, because it simply looks like a
sheet of fuzz covering a plant. Yet it retracts in a similar way to hydra.
I'm to sure what it feeds on. It could be photosynthesis, or it could eat
debris in the water, like a filter feeder. It's covering some blades on the
draw from hair grass and some of the baby tears. So far that's it. I would
like to find out what it is and if it's harmful.
I attached a photo of the fuzz on some dwarf baby tears that are the carpet.
As well as a photo of my taller dwarf baby tears.
<It's hard to tell from the photo, but if it really does retract when
touched, then some sort of Hydrozoan does seem likely, though there are
freshwater bryozoans as well. You really need to examine specimens under a
microscope, or at least a hand lens. Hydrozoans tend to look like jellyfish
on stalks, whereas freshwater bryozoans have distinctive polyp-like
subunits with a horseshoe-shaped feeding apparatus covered with tiny
tentacles. Bryozoans are harmless, but hydrozoans can pose a threat to tiny
fish and shrimps, potentially anything the size of a newborn guppy or less.
These aside, various red algae very commonly form hairy or fuzzy coatings on
plants, but despite their name, the freshwater varieties are rarely red in
colour. Red algae are difficult to control, and best physically removed and
then suppressed by optimising conditions to favour the growth of plants
instead. Fungi are the classic white fuzzy coatings, but they're normally
seen on decaying organic matter (such as wood) rather than healthy plants.
Removing whatever it is that's rotting is the best way to control fungi.