White Dust-Like Particles In Tank!

[FishSlime4L]

I have a 20 gallon tank with 4 balloon mollies, 10 harlequin rasboras, and 2 baby common plecos.

My water parameters are 0 ammonia, 0 nitrite, and 20 nitrate.

Anyways, I rinsed and added a second cartridge to my filter last week (leaving the original cartridge in so the bacteria gets transferred onto the new one) and 2 days after adding it, I started noticing white dust-like particles just floating around my tank as well as at the surface. I don’t know if there is a correlation between adding the new cartridge and the white dust-like particles. My fish seem to be doing okay since none of them are gasping at the surface or anything and none have died. I cancelled out the belief that my tank’s cycled was disturbed since my parameters are fine. Any ideas on what this could be and how I can fix it?

[Dreamroper]

I'm having problems with particulates in my tank too, but I've been planting new plants and cleaning for the last few days, so I'm assuming things will settle down here pretty soon. I've been cleaning the media in my HOB filter every day, sometimes twice a day and it definitely needs it when I'm doing it.

I also think I've been feeding the bottom of my flake jar of food which is too fine.

I'll read with interest any other comments.

Good luck,
D