Thinking of using a sand substrate for your goldfish tank?


I use sand in my goldfish tanks and LOVE it.

Sand is easy to clean…

… And aquascapers agree that it gives the illusion of a larger tank (as opposed to using gravel).

But not all sands are created equal.

Using the wrong brand of sand can actually create a nightmare of chronic cloudy water and clogged equipment!

After testing many kinds of sand, here are my favorites.

Best Goldfish Sand Substrate for Your Aquarium

Color White Black Variegated Neutrals Beige Gold Off-White
Name Sandtastik FlouriteΒ  Black Sand CaribSea Peace River CaribSea Crystal River CaribSea Sunset Gold CaribSea Torpedo Beach
Sizes 25 lbs 7.7 lbs, 15.4 lbs 5 lbs, 20 lbs 5 lbs, 20 lbs 5 lbs, 20 lbs 5 lbs, 20 lbs
Material Feldspar rock Volcanic (?) Clay Mixed river sand (?) Quartz Beach sand (?) Quartz
  • Clean white look
  • Soft on fish bellies & fins
  • Silicate Free
  • Striking black look
  • Nourishes live plants
  • Natural look
  • Large grain size
  • Won’t cloud water
  • Light natural look
  • Large grain size
  • Won’t cloud water
  • Natural look
  • Soft on fish bellies & fins
  • Light natural look
  • Large grain size
  • Won’t cloud water
  • May cloud water initially
  • May cloud water initially
  • May leach silicates
  • May leach silicates
  • May cloud water initially
  • May leach silicates
  • May leach silicates
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1. Sandtastik Sparkling White Play Sand

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No doubt about it:

White sand gives your tank a clean, fresh, bright look.

I used to shun play sand because it’s so fine, but if you wash it enough and use a sponge filter…

… (and ensure your equipment isn’t too close to the bottom)….

… No long-term issues.

But WAIT!!

Most regular white/neutral sand – be it play sand or aquarium sand – is usually made of ground quartz.



Quartz is rich in silicates.

Lots of silicates in your water leaching from your sand often leads to major problems with brown algae.

(I learned this firsthand.)

Silicates are the #1 food for ugly brown diatoms!

Yes, you can clean it off by hand.

(And why would you want to be dealing with it all the time?)

But if it gets on the leaves of your live plants it can KILL them!

Snails can only really help with smooth surfaces, and you need quite a lot of them to keep outbreaks at bay (which adds to your wasteload to the tank).


You can try keeping something Phosguard (removes silicates) in your filter…

But even if it works – it’s a continuing expense.

I specifically wanted white sand for my 29 gallon tank, and after some hunting I found Sandtastik, which is made of Feldspar rock instead of quartz.

Other aquarists also find it’s perfect in fish tanks.

I really like the soft texture for my fish as I’ve got an older fancy goldfish that likes to sit at the bottom occasionally.

When I used courser sands, I noticed he would never bottom sit on them but perch on a rock on his belly.

This indicated to me that the course grain sands are not comfortable for him.

Tip: I discovered if you wash this sand properly first and fill the tank with water landing onto a plastic bag you will not experience ANY issues with cloudiness! πŸ™‚

2. Flourite Sand

The other awesome sand I’ve been super impressed with lately is Seachem Flourite black sand.

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I love this sand in one of my planted goldfish tanks where I wanted a dark substrate.

The reason?

It’s a sand made of nutrient-rich clay – perfect for the planted goldfish tank.

Plus it looks super striking.

(Really sets off the fish & plants.)

Yes, it can be a bit cloudy initially, but me and many other fishkeepers agree – it’s worth the initial hassle to get the long-term results of a flourishing aquarium.

You can actually eliminate the need for liquid fertilizer dosing!

I also noticed the nitrates in this tank have dropped to 0.

After discussing this with SeaChem, they agreed that this clay could be supporting good anaerobic bacteria that are removing nitrates from my water.

Nice bonus πŸ™‚

3. Caribsea Peace River Sand

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I passed this one up initially when comparing goldfish sand substrate options – thinking it was gravel by the picture.

But it’s definitely NOT.

Caribsea’s Peace River sand is a formidable rival to the other brands discussed above, and there’s truly nothing else like it on the market.

The size is in between fine sand and gravel, slightly larger than 1mm each…

… Which has proven to be the most ideal size for allowing goldfish foraging behavior.

You can even use this type of sand to cap soil for growing plants, as it is far heavier than regular sand and won’t allow the dirt to escape when moved around by hungry goldfish.

The best part?

Unlike regular gravel, the majority of the debris sits on top rather than getting stuck in between the cracks and making a (potentially toxic) mess.

It has a beautiful, natural look that makes your fish & plants look like they are in a river in the wild.

4. CaribSea Crystal River Sand

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I really like Caribsea Super Naturals “Crystal River.”

My goldfish go CRAZY over foraging in this stuff, and cleaning it is the easiest of all the brands I’ve tried.

It won’t mess with your pH and is easy to clean and all natural.

The color is a great neutral shade as well.

As long as your suction isn’t too strong, the particles gently lift into the tube and fall back down – but the waste continues to get sucked up.

This allows me to push the tube all the way to the bottom of the tank and get just about every piece of crud!

Yay πŸ™‚

A cleaner tank = healthier, happier fish.

And unlike with gravel:

You get the benefits of something for the fish to forage in and enjoy without the hazards of choking and debris buildup.


It IS made of quartz.

And after struggling for about a year with a recurring brown diatom problem, I did end up switching this sand out because I got tired of purchasing Phosguard to remove the silicates.

(Something to be aware of.)

5. CaribSea Sunset Gold Sand

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For a natural, soft look, Sunset Gold is a great option.

I found that there was some cloudiness initially in the tank I set it up in…

… But this was quickly fixed by running a sponge filter for the first 8 hours.

(I was also lazy and didn’t wash it that well.)

This sand gives the tank a warm, inviting look and I like the little darker flecks that make it look like the bottom of a real riverbed.

You can also sprinkle in some larger pebbles to give it a VERY realistic riverbed appearance.

This sand is very fine and soft and kind of relaxing to move around πŸ™‚

6. CaribSea Torpedo Beach

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Torpedo beach sand is a lot like Crystal River.

The difference is really in the grain size, which is slightly larger.

It is also made of quartz.

The larger crystals are very easy to clean.

Benefits of Sand for Goldfish

Sand has many benefits for goldfish.

  • Does not trap debris, requiring less maintenance
  • Provides natural sifting behavior stimulation for foraging goldfish
  • Prevents hydrogen sulfide pocket production
  • Allows plants to root (unless your goldfish dig them up)
  • Enhances appearance of the aquarium

The Cleanlier Option

If you’ve ever had gravel in your aquarium, you know firsthand how downright nasty that stuff can get.

It seems like you can clean for AGES and never get all the debris out!

Fishkeepers who switch to sand from gravel almost always heave a massive sigh of relief:

“It’s so much easier to keep clean!”

This is because the fine particle size prevents waste from settling down into cracks and pockets, where it would sit and pollutes the water until someone disturbs it.

And the best part?

The waste tends to gather in areas of the tank where the current circulates, making vacuuming up all that poop in one fell swoop as easy as falling off a log.

Natural Behavior Encouragement

Bare-bottom tanks are definitely the easiest to keep clean…

… But they deprive the fish of the delights they have in sifting through and picking at things at the bottom.

In captivity, goldfish will be happiest when they can do what they would do if they lived in their natural environment – a pond or slow-moving river.

This behavior comes so naturally to them and gets them moving around their habitat longer, meaning more exercise and stimulation.

Why not let them do what they love?

I think it’s always a good idea to think of different ways to enrich their behavior and mimic natural conditions, especially by providing foraging material for them to graze on throughout the day.

How Deep of Sand Should You Use in Your Tank?

This is a good question.

My recommendation in general is not to use more than 1/2″ of sand at the bottom.

This prevents hydrogen sulfide pockets from forming.

(Nasty toxic pockets that can harm or kill your goldfish.)

Yes, with goldfish a shallower substrate depth can be a bit annoying because they really like to dig.

And you might have to sweep the sand every week or so to cover up any bare spots they might create.

The current from your filter can also cause bare spots.

But this isn’t a big deal to me since I usually have my hands in the tank doing cleaning or maintenance each week.

I don’t think you need to worry about really stirring it up each week like some fishkeepers do – since it’s not a deep layer.Β  I certainly don’t go crazy with this.


All that aside, if you have some deep rooting plants in your tank such as Amazon Swords, you can probably get away with using more than 1/2″ because the roots help to aerate the substrate and prevent these pockets from forming.

(Interestingly enough, some aquarists use deep sand beds as a method of filtration. Here’s an interesting article about that if you’re interested.)

Some people also keep Malaysian Trumpet Snails to aerate when they use deeper substrates – not that I would do that since they seem to be dirty little creatures.

They are used to turn the sand over.

Either way, I hope that helps clarify things for you.

Thoughts on Different Kinds of Sands

I already touched on why I don’t use sand that’s too fine.

But there are some other kinds I steer clear of too:

Some can have weird dyes or polymer coatings that can leach into your water over time.

I try to stay away from these.

The coatings are added to prevent the sand from influencing the pH (not a problem if you use Caribsea’s Crystal River).


White sand is something I will probably never try again.

The poop and any little speck of debris on the bottom stands out like a sore thumb.

The glare is harsh and unnatural.

And if you have any problem with brown algae… you can forget about white sand for long.

Wrapping it Up

I hope you enjoyed this article.

Did you learn something useful?

Have you ever used sand for your goldfish tank?

I’d love to hear your experiences in the comments below.

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