PFS and blasting sand are actually measured, all of the grains are around the same size and water flows easily through them (exactly the reason why PFS works as a filter)TexasDomer said:
It's an old thread, and yes, it appears to be misplaced.JimTheFishGuy said:PFS and blasting sand are actually measured, all of the grains are around the same size and water flows easily through them (exactly the reason why PFS works as a filter)
Play sand is just randomly-sized, so you could end up with tiny grains filling the spaces between larger grains, which reduces internal water flow and allows such pockets to form. Even if you do use play sand, frequently raking it with a stick helps distribute oxygen within the substrate and reduces the chance of pockets forming.
Also, I noticed you were talking about cories... Isn't this supposed to be a saltwater area? (This question is in the wrong place.)
I think there are silica-based blasting sands too, which are closer to the traditional "quartz" color.TexasDomer said:I don't have experience with those, only BDBS which is only black I believe.
Is 20/40 medium grade the right grain size.TexasDomer said:Play sand isn't always better (isn't it easier to form the anaerobic pockets in play sand?), and it's light colored - same as the PFS. I have Black Diamond Blasting Sand too, and I love it - dark black and perfect for cories.
Feel it with your fingers if you can. As long as it's not sharp, it should be fine. Most people use very fine or fine grit, but I use medium myself.Greenplant said:Is 20/40 medium grade the right grain size.