What's in my tank?

[Elliebean]

These particles are accumulating at the bottom of my tank. I've been using a manual siphon to auction the gravel.

Am I doing something wrong? Help!

 

[SherLar]

It could be a type of red algae that's been hiding on decor, or behind your heater or filter intake that's broken off and fallen to your substrate.
It could also be calcium or limescale deposits that accumulate in tanks with hard water, though those are usually more of a gray color.
Either way, I would advise you just remove it when you see it, and possibly do a full spectrum water test.