i was wondering what is the white dust like things that stuck on glass is ?? when the water current blows by ... u see them waving back and forth...? are those harmful??? are they algae???

Can you get a picture? It's likely that they are planaria, harmless but gross little worms that feed on the detritus in your tank, like fish poop and uneaten food.

When they arise in my tank I just make sure I keep the water very clean and wipe them off the insides of the glass.

thx i was reading about that ...but i weren't sure if its really worms .. i never seen them move... is there anyway to prevent it ???

If it really is planaria, then you can't really eradicate them from your tank. However you can limit their population by cutting down on the waste in the tank by either feeding less or cleaning more. They will often live in the filter and come out when you feed your fish, then dissapear again after.

ACtually, salt will kill the majority and the rest can be rid by cleaning the tank well and properly to eliminate excess waste that feed the worms.

That said - I doubt that you are seeing planeria. They actually look like little white inchy worms that wiggle in the currents and inch along on the glass, plants and bottom.

I suspect that you are seeing the very beginnings of algae as it starts growing on the glass. Before some types of algae get think enough for you to see a color, specifically, they can appear as a white or beige haze on the glass - sometimes with little bits that wave in the currents. If you run your hand over the glass it may feel slimey - and the haze wipes off easily.

To clean this, simply wipe the glass down at each water change.

Thanks daryl ... i think its algae tooo i don't see them move around and its on all the glass too !!! i'll panic if its all worms !!!