Need Help with Sand Bed - Please

[HowieUMD]

First some background. I've been running saltwater tanks for about 2 years now, and never have had many problems. I started with a 72 then upgraded and have had my 240 gallon tank initially setup in June with a 65 gallon refugium and 50 gallon sump and everything was going great. I then moved in the end of September and had to tear the tanks down to move them. I got the 240 set right back up after the move, due to the fish and live rock I had needing a home, but just now got finished setting up my sump and refugium in the basement with the plumbing. The main tank has run suprisingly well with no fatalities despite basically no filtration running outside the main tank since the move, meaning no skimmer or water running through to a sump/fuge for about 3 months, but it's now time for me to set this all back up so I can have it running right. The only flow for the past 3 months has been 2 Tunze 6100's inside the main tank.

In the main tank, I have about 300 lbs of live rock and a 2 inch sand bed. Everything I read basically says a sand bed of this depth is worthless, even harmful, as it's not bare bottom and it's not considered a DSB at this depth, but I do like the look of sand in my main tank. Is this true? I don't want it too deep, so I'm hoping my refugium, which currently has 3 inches of sand, can act as my DSB. I'm planning on adding another 2 inches tomorrow, to make it 5 inches.

The first question is am I doing harm to my system by keeping 2 inches of sand in the main tank, or will I be fine since my refugium will have the depth to take the advantages of the DSB? Next question, should I go deeper in the refugium, to say 6", or is 5" fine?

I see the detritus build up in my main tank on the sand bed. It's not too bad, but it's definitely accumulating. My hopes are that once I turn the switch on and start circulating the water through the overflows and down to the sump/fuge, it'll take out most of the detritus in the beginning. For a few seconds, I plan on aiming the Tunzes so they just hit the top of the sand bed to stir up the detritus once I turn my overflows on, which I hope makes most of it go up and down to the sump/fuge. I also just bought a detrivore kit and about 10 spaghetti worms from Inland Aquatics for the main tank and a refugium fauna kit from them for the refugium, which will also help. I have a lot of nassarius snails and a few cerith snails right now, but I know my pod and worm population is really low in the main tank, due to the move. The addition of mini stars, pods, and worms should definitely help, correct? When I moved, my rocks and sand had to sit in tubs of water for about 3 weeks, so most of the life I had died off back then, and I'm just getting to replenishing it now.

Anyways, I guess my biggest concerns are about the depth I should make the sand bed in my refugium, if it's safe to keep just 2" in the main tank since my refugium will have the DSB, and if the critters I have on the way will do the job in keeping the sand bed clean. I also want to raise a good pod population in the refugium, and am adding about 10 pounds of Chaeto as well. Sorry for the rambling. Any feedback would be appreciated!

 

[HowieUMD]

I know it's a long post, but does anybody have any feedback? Thanks.

 

[HowieUMD]

Sorry to be a pest again, but looking for some feedback please. Thanks.

 

[Ryan454]

I dont know why a 2 inch sand bed would cause any harm seeing as how it's to shallow to let any toxic gases to build and it's a place for biological bacteria to do their work aiding in the processes needed for good filtration. A bare bottom tank (in my opinion) is not the way to go but some people say it's better because they can simply siphon out any accumlatted detritis or whatever. A deep sand bed is also risky because of the anreobic (no oxygen) zones that could be disturbed there by letting toxic gases into the water that's why the plennum was invented. Please excuss any miss spellings.

 

[npaden]

Here's a basic thread that might help: http://reefcentral.com/forums/showthread.php?s=&threadid=732378

It gives some of the pros and cons of each method. Click on the links inside the post for more detail.

FWIW, Nathan

 

[coralnut99]

I run 3 different systems all with no more than 2 inch sandbeds. The refugiums run from 2 to 4 inches deep. They house a variety of sps, lps, and softies. I'm settiing up a 4th system that will house all the softies for my son to manage and these will have less than an inch, with a 4 inch bed in the fuge.

I have no nuisance algaes on any of the sandbeds, and no detritus accumulations. For me the key has been a variety of detrivores, a light fishload, and equally light feeding schedule. My 125 houses only a purple tang, and 3 anthias, for example, and I feed only once a day. The anthias are frine with this schedule and have been with me over a year, growing and beautifully colored. Lots of corals though.

Atlantic cucumbers (holothurians) are in each system as are the usual compliment of hermits and snails. Though when I checked last, the hermits have decimated the snails in my 125.

My 125 is actually 3 smaller dsb's that I combined about 2 years ago and ended being one big SSB. I had no problems with the DSB, I just wanted to try a different environment. I had read threads about the benefits of maintaining open water, so this tank only has rock work on one side of it creating a reef slope of sorts, instead of wall-to-wall rocks. The other side had just a huge rhodactis cluster and several very tall gorgonians. It's worked very well for me. I never saw the need to make any of the sandbeds deeper.

SSB's have worked just fine for me. I've seen the BB tanks and I just don't care for the look. That's just my taste at work, and it's worth nothing more than the 2 cents I've just put in. Just sharing my experience

 

[Zedar]

Sandbeds are fine as long as you can replace them without crashing the system.

And the need to replace them will happen at some point. That point depends on how often you feed the tank and how much life is in it.

This hobby goes thru fads like everything else in life. And most of them are just that "fads". But every now and then we learn something new and advance the hobby a little further along.

Ten years ago BB or very shallow substrate tanks were in and the "RIGHT way to do it". Then about 5 years ago alot of people started going DSB.
It became the new "RIGHT way to do it".
So what is the Right way? Maybe a little of both.

Right now there are alot of people going BB (Bare bottom) They're cursing DSB's because their tanks crashed due to the DSB.

So whats the scoop?

We'll just because the first time around things didnt work out for some people with DSB's doesnt mean that DSB's are all bad.
If at first you dont succeed.......... applies here i believe.

What happened to these tanks?

The Sandbed became saturated and could no longer proccess any more waste. They started leaking the waste back into the system and causing all the obvious problems that occurr when waste isnt proccessed: Hair algae, high phosphate and nitrate levels etc.

So instead of looking at it from a different angle, alot of people have abandoned the DSB all together.

But heres what ive done........

Ive made the DSB a seperate and exchangable system unto its own.
Let me explain...

You are correct in questioning the depth of the bed. It does have to be deaper then 2 inches to be effective, and it does have to be sand of the proper size.
The sandbed completes the nitrogen cycle.
In the upper half of the bed, bacteria act opon the waste and do their thing. They convert the ammonia and nitrite to nitrate they are known as aerobic bacteria.
Further down in the sand their is a different bacteria known as a denitrfying bacteria that break down that nirate into nitrogen gas thus completing the cycle. This area is known as the anoxic zone.

So having a 2 inch bed isnt alowing the nitrate to to be proccessed.
You need to go deeper.
All the info you need to know is here.

http://www.reefindex.com/browse-all_about_sand_beds-25-1.html

Now in all of these systems the DSB is in the main tank. or it may be in sump but its one big bed.

What ive done is this.

Ive built a multi-chambered container for the sand bed. If the bed is one continuous bed then you cant disturb it or you will upset the balance between the aerobic and anoxic zones, and kill possibly all your tank inhabitants.

You cant wait for the bed to become saturated so it best to replace it every few years. Every two years if you really want to be safe.

By having three SEPERATE beds in the chamber, I can swap out "one at a time" each individual bed without having that great an impact on the whole system.

Typical routine would go like this.

1.Remove the water from the container. I do this by turning off my pumps and alowing the water to drain into my refugium.
2 Using a shopvac, vacuum the sand out of one of the chambers.
3. Clean out the chamber thoroughly.
4. Add fresh sand to the proper level, about 5 inches of sand should do it.
5. turn the pumps back on and resume normal operation.
6. after 6 months do the same thing to chamber two then repeat for chamber three etc.

By doing this we get the benifit of DSB's without the downside.

Alot of people have gone BB in both tank and sump.
They use mega skimmers and mega flows to remove the waste before it breaks down.
This makes sense for an SPS tanks but isnt practicle for an LPS tank.
But the BB method is what we need to aim for just going about it differently.
You want a BB tank but since the flow cant be great enough to keep detrus suspended you have to blow the rocks off once a week with a turkey baster and then remove it after it settles to the bottom.
In otherwords you have to manually do what they(the BB people) are doing with high flow.
Because you can aim the turkey baster in between the LPS corals and selectively get the crap out.
But the bottom line is you gotta get it out one way or another.