Source of black/dark sand for aquarium use

[Quark_VI]

Hi,

Anybody know of a source of black/dark sand that is suitable for aquarium use.

Have considered using some west coast sand (wanganui area) but won't be taking off of the beach as the shells etc. will harden the water. Was considering taking some sand from further inland but that will probably have the same effect.

From what I have managed to google the black is due to titanomagnetite, a type of iron ore, no idea if this will be a problem.

Also seems that iron slag based "sand" is available in the states which I wouldn't want to use due to the high iron content.

I usually just use silica sand suitable for pool filters but would really like to try something darker to show up the fish better. Reason for sand as opposed to gravel is that I keep catfish and don't want to damage their barbels.

Will do the usual boiling washing routine with any sand.

Appreciate any advice/opinion.

[sharn]

i have sand in two of my tanks i got from bunnings/benchmark. its a medium-dark grey and quite fine. it hasnt had any effect on my water params as i had it in my axolotl tank for 6 months before i used it in anything else just to see if it would harden the water (itd be a good thing in my area haha). the sand was plasterers sand and was the finest and least sharp looking they had. 5 bucks for a 20kg bag or something like that, it is pretty dirty tho so i put it in a pillow case to wash then baked it just to be sure