My Water is Dingy?!

[amyw16]

We have had our Betta fish, Sam, for about 2 1/2 wks. We have a 2.5 gallon tank with a heater, filter, thermometer, two fake plants and a cave/tunnel. I've been doing a 50% water change every other day to keep the ammonia at 0. The Ph was ~7.2 earlier today. I use water test kits for those. I have test strips for the nitrate, nitrite, etc. and those all seem to be okay too.
Yesterday, the water started looking dingy. Not cloudy, but dirty. I did a 50% water change, but it still looked that way today. I changed the filter, although it didn't look dirty. After a few hours of no change, I put the drops of stuff that is made to clear up the water. It said it causes the particles to get stuck together so the filter can get them. Still no change though.
I also noticed on some of the shiny rocks it looks like there are black specks all over them.
I'm not sure what to do now to fix it. Any advice would be great!!

[ErinBBC]

Hm...what color are the flakes/pellets you feed him? The only think I can think of is that the black specks are poop, Marley has brown poo because his pellets are brown. If they aren't settling to the bottom maybe it's that your filter is making a good bit of current so they keep swirling around in there.

I'm no expert but that's all I could think of!

[amyw16]

Yeah, his pellets are dark brown. They seem to settle though and become bigger and lighter brown. I'm not sure what's going on. I'm going to change half of the water again and see what happens. I don't know what else to do since all the levels seem okay. Thanks for the input.

[JMeenen]

Maybe get some aquarium wipes and wipe down the inside of the glass ( No need to empty the water theyare fish/plant safe) Maybe there is alge or some kind of buildup on the glass making the water look dingy..brownish?

[Kim]

Does the water appear clear when you put it in the tank? If not, it may be minerals or silt. Algae may be another culprit, try scraping the sides of the tank with a clean razor or toothbrush. There are also some types of algae that float in the water. I think that they sell products to clear up this problem. Could be worth a try. The brown spots that appear to get larger and lighter may be poop. When it gets saturated it will expand and consequently look lighter in color. This is just what I thought of, I am by no means an expert. Hope the problem clears up.

Kim