Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Soil Master Select and Turface (Similar materials to Oil Dri, Safe T Sorb):
High CEC retains fertilizers. I was doing EI, then backed way off and the plants are still doing well.
It is too light to hold down the plants when they are first planted.
These materials remove the KH from the water, dropping it to 0 degrees, and allowing the pH to drop to the bottom of the test. (6.0).
When I mixed Turface and Coral sand this did not happen. The coral sand gave the Turface all the carbonates it wanted, so the water stayed at the KH and pH that I set it at.
I like the dark, not pure black look of the SMS charcoal. The Turface is too light IMO. (I have one of the browns, a sort of golden tan)
PFS (I do not know what brand, just a 30 mesh graded sand) is heavier, so the plants stay down, but no CEC. Gotta stay on top of the fertilizer. Easy to vacuum, as long as the intake of the siphon is not buried in the sand. Heavy enough to fall right back out.
Combining the 2:
I made a rock wall with SMS in back and PFS in front. The sand sifted through and under the rocks, along the bottom of the tank. The SMS got blown around and over the rocks, and drifted between them. I now have a tank with PFS on the bottom, SMS on top, and a nice line of rocks.
I did a similar thing with Turface and PFS, but used expanding foam like mortar between the rocks. Sand stayed in the sand place and Turface stayed in the Turface area, except for a few grains now and then that get kicked up by the fish.
I never used play sand in a tank, but I did set up a demonstration for the local aquarium club with lots of different substrates. The play sand container settled in layers with the fines staying suspended in the water for several hours, finally settling on top of the real sand like a scum of mud.
3M Colorquartz (no longer available) is a really nice way to go if you are thinking of sand-like particles. Look into the swimming pool construction trade and get the colored quartz material that is added to the inner layer of the pool to give it some color. (Maybe Pebble Tech?) I have a tank with the finest black Colorquartz. It is very dense, so it stays down and holds the plants really well. No CEC, of course. No clouding, either. These materials are available in many colors, too. You might think about blending 2-3 colors for a more natural mix. Maybe black, grey and deeper brown for a dark bottom, or tan, light grey and cream for a lighter colored bottom.