what type of sand to use in freshwater tank

[redtailcatfreak]

i have a tank setup and with fish. chiclids, gourami, rtc, and pictus cat.
currently i have large black river rocks covering the floor. but the plants have a hard time stayin in places so i want to get a black sand to put on the bottom then the rocks on top to help hold the plants. is there a type of sand that i can put in that wont hurt an established tank or should i just leave it as is?

 

[HarleyK]

Howdy,

If it's for plants, then get playsand. It still contains clay and serves as natural fertilizer. However, it's messy. Best to empty the tank to do it. No problem with regard to it being an established tank, just keep the filter alive during the process (e.g. circulate water in a bucket). Black sand alone looks unrealistic to me, I mixed my black 3M colorquartz with brown and grey.

HarleyK