Deep sand bed? Lfs says no

[jasimek]

I have a 90 gallon with live sand at I started with...it is only about 2 inches at the deepest portion with many areas significantly less due to power head movement. Lfs said not to add non live sand or any sand at all cause it can cause more problems...do u agree with this or not?

 

[jasimek]

I was plannin on adding about a cup of sand a week

 

[Patrick Bateman]

Yea I wouldn't, you could kick start a mini cycle in your tank by adding more sand/LR to an established system. However a cup of sand/week on a 90 gallon doesn't seem like it would really be an issue. I'll let someone with more experience have at this one.

 

[drparker]

New sand won't kit start cycle per say. The silica in the sand will kick start a diatom bloom but that will pass.

TO DSB or not is a constant discussion with pros and cons on both sides. I'd say stay where your at or go to at least 4" or more. Between 2 and 4 inches just adds problems without any benefits.

A true DSB will help keep nitrates down, you do need to make sure to replenish the microfauna that lives in it every year or so to keep it healthy. You don't want any sand sifters that eat the microfauna in your tank either.

 

[SushiGirl]

Between 2 and 4 inches just adds problems without any benefits.

I keep seeing this said, but haven't heard why or what kind of problems. Is there a thread or article somewhere I missed?

 

[RobsFishTank]

I have a 6 inch sand bed. I like to give my goby and pistol shrimp plenty of sand to play with. I also have my rocks buried down to the bottom glass so they dig deep. I can only guess what crazy tunnel systems they got down there.

that is my reason for a deep sand bed.

 

[madmauler9]

I keep seeing this said, but haven't heard why or what kind of problems. Is there a thread or article somewhere I missed?

From the little bit I've read it looks like the denitrifying benefits of a DSB won't happen in less than 3 inches of sand because it isn't anaerobic enough.

 

[Jocko]

The easiest way to approach the sand bed issue is to just forget about the idea of a DSB having benefits. People run tanks with every possible amount of sand down to bare bottom so obviously a BSD is not needed to be successful. So if a DSB IS giving you a benefit, just think of it as a bonus, not a requirement.

So anyhow, my point is, I recommend approaching the sand bed issue strictly from an aesthetic/practical point of view. Got a goby, pistol shirmp, etc. that needs deeper sand? Just like the look of deep sand? Then go for it. If not, just go for what you like. The rest of your system design will have WAY more impact on your success than the amount of sand you have.

 

[MaxxedMan]

You can always add 8" of sand in you refugium, and keep your display with 2". Down there nothing is digging in it, and you can create the depth you need with a lot less sand.

 

[SushiGirl]

From the little bit I've read it looks like the denitrifying benefits of a DSB won't happen in less than 3 inches of sand because it isn't anaerobic enough.

But that's not a "problem" as Jocko just put it so well. No one is expecting DSB benefits from a shallower sandbed. I'd just like to know what the actual problems are, or if people just read an opinion with no facts behind it & are repeating it as fact now, like so many other things.

I personally agree with Jocko...and sorry for hijacking the thread!

 

[BigBarnacles]

If you want to learn a lot about deep sand beds checkout Newyorksteelo on YouTube. He's got at least three videos on deep sand beds. Very informative.

 

[drparker]

At depths starting at about 2.5" inches Hydrogen sulfide can form in the sand bed. If the sand bed is disturbed and the toxic hydrogen sulfide is released in the water stream you'll have a tank crash that can kill almost everything in the tank. The bacteria that reduces hydrogen sulfide does not exist until the sand bed reaches 4" or more depth.

So a 3" sand bed has the potential to form toxic hydrogen sulfide. If you move a rock, drop a power head or add sand sifting fish that disturbs a pocket of hydrogen sulfide you'll get a tank crash.

See DSB explained

See Hydrogen Sulfide

 

[Playa-1]

You could add a bit of sand back to the DT. I wouldn't put in what is considered to be a DSB in the DT. If you're wanting to go with a DSB for what ever reasons then maybe consider it in a sump or some type of RDSB.

 

[fishgate]

My LFS always has contrary advice to what you get on these boards. But then again, they only need to keep the fish alive for a few weeks.

 

[SushiGirl]

At depths starting at about 2.5" inches Hydrogen sulfide can form in the sand bed. If the sand bed is disturbed and the toxic hydrogen sulfide is released in the water stream you'll have a tank crash that can kill almost everything in the tank. The bacteria that reduces hydrogen sulfide does not exist until the sand bed reaches 4" or more depth.

So a 3" sand bed has the potential to form toxic hydrogen sulfide. If you move a rock, drop a power head or add sand sifting fish that disturbs a pocket of hydrogen sulfide you'll get a tank crash.

See DSB explained

See Hydrogen Sulfide

Thank you!

 

[dzhuo]

Sushi,
Take a look at this experiment performed by Robert Toonen (Ph. D) and Christoper Wee: Feature Article: An Experimental Comparison of Sandbed and Plenum-Based Systems: Part 2: Live Animal Experiments. It's an extensive study regarding the affect of various types of sand bed and their function as nutrient export and control. The bottom line: There is no significant difference between any of them. It really don't matter much.

 

[SushiGirl]

Thanks very much, dzhuo.

 

[mguiling]

one of the most frustrating thing about this hobby? The blind leading the blind.

+1

 

[scarface70706]

lol ive been running a 3" sand bed for about a year without any problems. i have snails that stir up my sand all the time and my tank is doing just fine. theres nothing wrong with 3" sand beds. 2 of my buddies run sand at about 3" with no problems. i also know about 5 LFS that have most of their tanks and personal tanks with 3" sand beds and their systems have been running for yrs. im not trying to cause a debate or argument but the "3" sand beds are bad" premises in this thread are inaccurate.

 

[doctorgori]

New sand won't kit start cycle per say. The silica in the sand will kick start a diatom bloom but that will pass.

...that was debunked a lil while back

TO DSB or not is a constant discussion with pros and cons on both sides. I'd say stay where your at or go to at least 4" or more. Between 2 and 4 inches just adds problems without any benefits.

...anymore I'm convinced you can have problems (or not) with sand of any depth


A true DSB will help keep nitrates down, you do need to make sure to replenish the microfauna that lives in it every year or so to keep it healthy. You don't want any sand sifters that eat the microfauna in your tank either.