3mm-15mm Gravel with Laterite?

[shadowstars123]

using mineralized topsoil takes a lot of the risk out of using a soil substrate, as it helps minimize the amount of organics in the soil. Either way, both should be capped with something. They work great for planted tanks, but if you aren't planting I wouldn't bother.

As far as sand goes, check an industrial or pool supply place for 3m colorquartz . It's been discontinued but a lot of places still have it available or a replacement product available. It's a colored sand that has been ceramic coated so it is very smooth and durable. I believe it is used by contractors to create non slip surfaces around pool areas.

As far as I know there are only 2 kinds of pool filter sand, the silica type and diatomaceous earth type. The DE type would be fine if it's in rock form, but obviously not if it's a powder.

I wouldn't worry too much about diatoms, they happen to tanks with sand and those without, just pick whatever you like best and go with it. I do suggest going with something other than playsand though, it compacts too much and end up rinsing half of the bag away because it is silty.

Are there any black/ brown pfs?

 

[jetajockey]

not that I know of. I've heard of a yellowish colored one but I can't confirm. PFS is used in..well you guessed it.. a pool filter, so multiple color choices really isn't something they focus on.