Seachem Fluorite Onyx Sand Substrate, 7.7 lb (67135030)
$20.15
Price: $20.15
(as of Apr 13, 2025 21:33:18 UTC – Details)
Sachem has been providing quality aquatic products at value pricing for years. Whether you have a beginner setup or even up to advanced seasoned aquatic experts, Sachem provides everything you need for quality, healthy aquatic environments.
Product Dimensions : 5 x 2 x 4 inches; 1 Pounds
Item model number : 001187
Date First Available : November 26, 2013
Manufacturer : Lambert Vet Supply
ASIN : B00GIVN68S
Country of Origin : USA
This product is easy to use
This product adds a great Value
This product is Manufactured in United States
Age Range Description: All Life Stages
Included Components: None
Customers say
Customers find the aquarium sand visually appealing with beautiful color and appreciate its functionality, noting that their plants are flourishing and it provides valuable nutrients. However, the sand receives mixed reviews regarding its quality, with some finding it very fine while others say it’s not sand at all. Moreover, customers report issues with cloudiness as the aquarium water becomes murky, and the sand creates dust even after thorough rinsing. The value for money is also mixed, with some considering it good for the price while others find it not worth the cost.
AI-generated from the text of customer reviews
Denise –
Beautiful color and texture! We love this sand and so do the fish and shrimp!
I wanted to review this sand because I have seen many bad reviews on the dust. This is the second tank I used this sand and both times I have been incredibly happy with it. I love the color and look. Yes, its grey not black. I used the Seachem substrate calculator from their website to determine how much to buy based on the amount I wanted, it worked perfectly. I would recommend using the free tool to determine how bags you will need. The picture is a 75 gallon tank and I used (8) 15.4 lb bags.So yes the sand is dusty! But its natural SAND. It is to be expected. I placed 2 bags at a time in a 5 pound bucket and rinsed the sand but just until the milky white color started to disappear, never clear but cloudy water. I then used a cup and scooped the sand one cup at a time and slowly released it to the bottom of my tank. I did no more than 2 bags per day because the tank was already established and I did not want to lose anything. Placed 2 bags and allowed it to settle for 24 hours. 4 days and it was complete. The tank is clear and I did not lose any fish, shrimp or plants. There wasnât much on the plants that needed to come off, the filter removed the majority of the dust that was left.If the tank was not established I would have placed all 8 bags at one time and allowed the tank to clear. The sand is beautiful and worth the wait. The fish and shrimp are happy and water is clear. We also have this same sand in our 5 gal. Shrimp tank. I do use a water softener pillow in my filtration with this sand for the shrimp.
Fernando Soca –
Dirty, cloudy, filthy, please clean
Do NOT underestimate how dirty this is! I ultimately had to hand wash it in the bath tub for 2 hours straight and it still clouded my fish tank. It also left behind dark residue in the tub so be careful when you clean it. I really love the color and how it looks. It’s perfect to supplement the sand bed I already use for my plants and my Cory catfish don’t mind it. It’s not too fine but not course enough to hurt them so I’m happy with it. For 15lbs at $11 it’s the best deal for sand. Just be careful.
AK –
Not black, but looks great. Rinse, rinse, rinse.
This took a LOT of rinsing. Like…a REALLY LOT. As other reviewers have said, it’s not actually black, but a mid-ish range grey. Still looks sharp, though, and was otherwise easy to work with. I haven’t noticed it messing with the pH too much. Maybe a slight bump, but not a wild swing at all, but it’s a big tank. So far so good.
Jesse –
Be prepared to rinse and repeat over and over
I made the mistake of thinking this was a black sand which it isn’t, it’s more of a light gray. so after buying two bags I bought another type of black sand and mixed the two. I love the end result. This product was however a pain to clean to say the least and my aquarium was super cloudy (even after rinsing half of the bag for at least 30 mins) but that went away overnight. All in all I’m pretty happy with the end result.
Jennifer B. –
Uncontrollable dust, not good for my fish
I read all of the reviews on this sand before I purchased it. I thought, surely I am capable of rinsing it well, and dark gray will look nice in my new tank.Wrong.First, it is a very light, ashy gray. That’s a matter of preference, but I truly have no idea why they named it “black.” On the gray spectrum, it’s closer to white than black.I rinsed it REPEATEDLY. Over and over and over again. Carefully filled my tank. Gave it several days for the dust to settle again. But any time I did ANYTHING in the tank – add a new plant, carefully vacuum the bottom, move a decoration – there were the clouds of dust again. It would settle – everywhere. Every decoration, every plant, every glass wall was coated in gray dust. The only way to get it off the plants was to hand massage each leaf after all the dust had settled.Most importantly, it wasn’t good for my fish. All of their poops were the same color as the sand, which made sense since they were swimming around in its dust. My two zebra loaches swam around like maniacs, never resting, and I finally noticed their bellies had turned red!After two months, I decided to bite the bullet and switch it out. It took me several days to remove it all, because the water would get so cloudy I couldn’t see what I was doing or whether I was about to murder a fish. (And yes, I was being careful).I went with Imagitarium Black Sand, and I love it. It’s not all-natural; people have recommended beach sand and other similar products if all-natural is important to you. But it was dust free when I rinsed it, went in easily, doesn’t stir up dust when I move it. It’s holding my plants well. And most importantly, my fish’s poop is now the color it is in my other tank, and my loaches, while still very active, spend time resting and digging around on the bottom of the tank, as loaches do.I suppose there might be circumstances where someone would love this sand enough to put up with the dust. Otherwise, I think there are better choices. And I would absolutely not use it if you plan to have any kind of sensitive bottom dwellers – loaches, cory cats, etc.
SaxplayernTX –
Nice but when you have to clean….
The sand is very fine which apparently is good for plant roots (??). HOWEVER, you will spend HOURS sifting this again and again and again to remove the fine dust that accumulates during shipping! If you don’t, VERY cloudy aquarium (almost as bad as London fog, lol)…Once you do get it into an EMPTY aquarium, and plant the live plant roots into it, you then have to VERY carefully pour the water onto a dish that you place on top of the sand (one cup at a time!) to avoid clouding the tank again. I like the appearance, BUT is it worth all the hassle? NO!!! EVERY time you do a water change, it clouds up the whole tank and takes about 48 hours to fully settle (on a 10 gallon long tank), by which time if you have any live plants with larger leaves, they are totally covered with grey dust!A waste of money and I am now going to have to strip the entire tank down, clean it out totally and use a different substrate and start all over again! Glad I hadn’t put any fish in it yet!
Alberto A. –
Excelente sustrato, solo hay que enjuagarlo bien y tener cuidado a la hora de llenar la pecera de que no haga turbulencia para que el agua se mantenga transparente.
OntarioGuy –
This is the second aquarium I have used this substrate with. I have a mixture of Seachem Onyx Sand and Grey Coast (supposedly they are the same – just marketed for fresh vs salt). After buying a bag of each I can confirm that this is true.The substrate is a nice mix of coarse gravel with small and tiny pieces. The biggest thing to make sure that you do is to wash it. It produces a lot of dust that does not settle and will stay suspended in the water for ever. Give it a good rinse and you will love this substrate / gravel. If you do not rinse it – you will spend weeks doing gravel vacuums regretting ever using this.Plants love it and my trumpet snails love digging in it. Rabbit snails do have a harder time moving around on the smaller gravel though.You do lose a good amount of the bag through washing – maybe a quarter (25%) will go down the drain as you wash it – so if you think you need 2 bags buy 3. Best way is in a bucket with a hose or in a cup and your hand mixing slowly – most pieces will go through a strainer.
Pletzer Daniel –
1. The sand is grey-ish which looks pretty natural ..2. It’s a natural substrate – so lot’s of fine sand …3. therefore, wash it as you would do with any other ‘natural’ sand – 10-20 times is no hassle (even if it takes 30-60 minutes to do) and will get rid of most of the fine sand …I disagree with bad ratings based on the fact that it is not clear right away – it’s not a chemically treated sand …
Steve Milligan –
Good value and really helps make a natural looking tank (I mixed it with a light coloured sand and just a small amount of gravel). Needs a really good rinse, but that’s to be expected
Nicolas –
Le gravier est top, esthétiquement un peu plus clair que ce que j’imaginais. Son poids est bon et permet le nettoyage du substrat sans aspirer tous les graviers contrairement au manado. Son seul défaut est son nettoyage, c’est un substrat très très poussiéreux, une véritable galère à rincer.