I get the impression that Onyx sand is really more like fine gravel than actually sand. Is this accurate? Is it less likely to cloud up and so forth?
Onyx sand question
- Thread starter Karlsbad
- Start date
yes i think that's the case, although they may sell it finer than that, but the onyx sand that i've seen is like fine gravel
Isn't it black? There's a picture in in 80gJoe's tank specs I found searching for Onyx that looks like really fine blue gravel and it says Seachem onyx substrate. Probably not cool to link to his specs page 
http://www.seachem.com/seachemframeset.html
If you go to the prducts page you'll see that actually this company sells both sand and gravel, one is just ground up finer.
If you go to the prducts page you'll see that actually this company sells both sand and gravel, one is just ground up finer.
I'm actually thinking of using it for my Oscar. My tap water is like 8.2 ph and 120 ppm buffering. I think it would be comfortable for him to dig in than most of the gravel I've seen. Maybe I'll scatter some pebbles for him to move around like he likes to do with the yucky blue and white Wal Mart gravel he has now. 
Would that be bad? Will it lower my Ph or raise my buffering out of healthy range?
Would that be bad? Will it lower my Ph or raise my buffering out of healthy range?
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Onyx sand is sorted at 1-5mm sizes, so is ideal for planted tanks. Technically by USDA grading, sand is up to 2mm, gravel 2mm and up to some large figure. Onyx would straddle the border as it were.
Onyx gravel is too large IMHO.
It is not black at all, gray is the best description.
Onyx gravel is too large IMHO.
It is not black at all, gray is the best description.
It seems like my safest choice for a fine gravel that won't cloud my water with an abrasive grit that would hurt my fish to breath like I would be afraid of what I consider like beach sand doing, of which I have no idea what the metric size is. This is what I'm thiking of when I ask if its not actually 'sand'. Darn I wish I had some idea how big a millimeter is. DOH the stress 
. I was originally thinking I wanted something in a mixed brownish more naturally colored fine gravel like the texture I'm thinking onyx sand has, but I don't seem to see anything at any LFS or chain. I could feel reasonably comfortable using non fish 'gravel'(even though the 'gravel' that I'm seeing doesn't really fit what I'm looking for), but I don't think I want to get too creative.
. I was originally thinking I wanted something in a mixed brownish more naturally colored fine gravel like the texture I'm thinking onyx sand has, but I don't seem to see anything at any LFS or chain. I could feel reasonably comfortable using non fish 'gravel'(even though the 'gravel' that I'm seeing doesn't really fit what I'm looking for), but I don't think I want to get too creative.
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Thanks, this stuff sounds cool I just wish I could get it in brown or varying shades of brown better yet.
The seachem website says it has some buffering capacity. I thought that meant it would lower PH, but there are posts that make it sound like it will raise PH. I thought buffering and PH were basically opposites of each other.
The seachem website says it has some buffering capacity. I thought that meant it would lower PH, but there are posts that make it sound like it will raise PH. I thought buffering and PH were basically opposites of each other.
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I have onyx sand in 2 of my tanks. Both are fully planted and with a black background it really makes the plants stand out. I havent noticed any differences over gravel as far as ph goes.
But if your not going to plant the tank I would look at cheaper substrates. And gravel vacs with sand are trickey. With an Oscar thats produces alot of waste I would look a better grade gravel.
Good luck Tim
But if your not going to plant the tank I would look at cheaper substrates. And gravel vacs with sand are trickey. With an Oscar thats produces alot of waste I would look a better grade gravel.
Good luck Tim