So Confused...

[idgy]

OK, I have done my homework and I am still confused about DSB or shallow sandbed.

I know all the positive points to a DSB but I am still unsure of what the negative points are.

Can anyone shed some light. I am starting a FWLR tank and not sure if I need a DSB or if a shallow one will do just fine!

Of course I want to use LS.


Thanks!

 

[mojoreef]

Let me see if I can muddy up the waters a little more. lol
A DSB is a bacterial system that is designed to reduce nitrogen based products. Kinda like composting. What it is not designed to do is to take care of the other products that are not nitrogen based, products such as phosphates, silicates and pretty much everything else. Also the sand used is saturated with phophates prior to entering your tank and when the bed goes anaerobic and the sand begins to melt these Phosphates are leached back in.
According to the dsb experts the concept is that it facilatates the export of algae, or in simple terms you will grow algae in it and when you harvest it you are exporting the nutrients.
A dsb will work but it is more designed to create an enviroment for critters that are more nutrient loving. Corals such as softies and some LPS will trive in this type of tank. SPS and simular corals perfer a more nutrient free enviroment and thus this would not be the best system for it.
You have to look at a DSB as if it were a sponge. It will be very forgiving to you when it is empty or not full. Once it is full thier is little more then you caan do then to replace it.
Thier are methods and husbandry that can extend the life of a DSB also. As per SSB they are the same as a DSB its just that the sponge is less and thus its life span will be to.


hope it helps


Mike

 

[wrightme43]

Big question with alot of opinions on it.
Here are mine. Others have valid and differing points on this.
Ok Deep sand bed on tank glass bottom. Supposedly oxy is depleted in the first 1-1.5" and you have a anarobic area underneath. Not to get into big long deal but the bacteria that live there are not the most efficent processers of nitrate and waste products, and it can form hydrogen sulfide gas
Deep sand bed with plenum method.
You have a raised sand bed leaving 1.5 underneath for a water plenum. In this method supposedly you have a aerobic area (high o2) an anoxic area (low o2) and a slightly less anoxic area (low o2) in this method the bacteria are supposed to be able to convert nitrate to nitrogen gas with out making hydrogen sulfide and are supposed to do this with a much more efficent biological process.
The shallow sand bed method. Since this is to be a FOWLR tank I would recomend this method. The sand remains mainly aerobic and is able to effiecently process waste to nitrate, since you are not going to have coral nitrate is not such a issue,with water changes and a good skimmer it will in my opinion work just fine.
Remember these are only my opinions and others may have a better explanation for you. HTH Steve

 

[MikeS]

As per SSB they are the same as a DSB its just that the sponge is less and thus its life span will be to.

The Sand Junkie cometh.... :lol:

hmm...2 big differences....the SSB isn't going to provide you with an adequate anerobic zone to be effective as a nitrate reducer...

And a SSB will be much easier to "clean"...ie you can manually remove waste from the SSB much easier than a DSB without having to worry about disturbing an anerobic zone...

MikeS

 

[idgy]

What if I went inbetween a deep sand bed and a shallow sand bed? Not deep and not shallow? What would I be dealing with then? OK, so each of them has pros and cons!

 

[FishyinKy]

Idgy, that really doesn't gain you the benefits of anything just creates the problems. I am a huge dsb fan and yet in my sps tank after looking and studying I plan to only have half an inch of sand in the bottom. . . If I have that much. Deep sand beds are wonderful and they look wonderful but they are a lot of work to keep alive and to maintain. I think that the best thing for people to do who haven't decided which way to go is to think more about what they want to have in their tank. In my dsb tank, gorgonians, lps abound and thrive. As do xenia and anthelia. But sps, even with the use of a skimmer, just don't have the performance that I would like them to. That's my experience, hope that helps.
Mac

 

[mojoreef]

Idgy I would go one way or the other full out. Go full dsb if you want to use that kind a filtration on your tank. if not and it just a for looks thing then go with a thin layer as Mac has done.


Mike

 

[fishermann]

You say you are going with a FWLR tank. IMO having a high fish load is not good for a DSB as they contribute alot of detritus which the causes alot of crap sitting in your tank to get processed by the DSB. If you are going to have mainly a fish tank I would personally have a BB so you can vac the detritus easly out. You could go with some heavier CC up in front of the rock work so you can vac it easily, but remember you are going to have to vac more if you run a shallow substrate because it well collect and hold more detritus instead od keeping it in suspension for the skimmer to grab as in a BB system. IMO a DSB is a good system for people who want to keep mainly softies and LPS corals because it feeds them, but with very FEW fish, this well help keep it going and not haveing algae issues to constantly deal with hopefully. In between with a SSB and high fish load if you use sand you are going to have alot of problems IMO because you can't vac sand. Hope this helps.

 

[idgy]

"You could go with some heavier CC up in front of the rock work so you can vac it easily"

I am sorry what do you mean be CC?

Thanks!

 

[fishermann]

Crushed Coral or a heavier substrate.

 

[idgy]

Ok, I understand and thank you! But I have one more question, Wouldn't a cleaner crew do a lot of the clean up or do you still have to vac up with a cleaner crew.

I appreciate your help and thoughts about this topic!

 

[fishermann]

Idgy what happens to the stuff they eat? Cleaner crews as a savior for keeping your tank clean is a term greatly over used IMO. They may in a small way keep things stirred up a little but remember they poop 90% of what they eat so you still have to do your tank husbandry, which there are no short cuts too.

 

[aquariumdebacle]

Massive water changes on a regular basis can help counteract some of the deficiencies. Back to your experiment with the "renewable plenum" last summer: Albert Theil gave a talk here (Seattle) in 1996 and stated that the plenum water needed to be removed periodically because it would build up with nitrates. Does this sound familiar? I personally would like to investigate a DSB with a plenum that has a reverse flow and a turnover rate of weeks if not months.

 

[idgy]

Ok to summarize, if I am only plan on a tank with fish and live rock I should go bare bottom (blush)! But if I want soft coral etc., I should go with a DSB?

 

[gobie]

Ok I Started Out With 1" Of Med Grade If Sand In My Tank And I Had All Sorts Of Critters Crawling Thru It. Recently We Went Thru A Great Salt Debate Here On R.f. I Think The New Salt That I Was Using At The Time And Some Other Reasons Caused My Tank To Go Thru A Drastic Salinity And Ph Shift. Now This Caused Most Critters In My Sand Bed To Die Off In A Very Short Peroid Of Time. So Siphoned Out Out More Than Half Of My Sand Bed. Which Leaves Me With May Be 1/8 To 1/4 Of An Inch Of Sand. What Type Of Impact Would This Have On My Queen Conch And Cucumber If I Removed All The Sand.

 

[fishermann]

Idgy IMO a DSB with VERY FEW fish is good for softies, but you said you mainly wanted fish and IMO a BB is best because of being able to get the waste out of the tank, now this is all relative to the size of the tank, what is a few for a 60gal. verses a 250 gal. is different.

Gobie I have a BB with a cucumber, as far as conchs go Mojo on another thread says he has a bunch in his BB.

 

[idgy]

Ok, as you can tell I am new to all this and I want to do this right! So if I was going to have soft coral than I should a deep sand bed and ONLY A COUPLE of fish? Fish that would not bother soft corals. I am planning a 58 gallong tank so if I went with DSB and soft corals would 5 fish be too many?

And if I am going to have just fish I should go bare bottom with maybe some crushed coral in front of the Live Rock?

 

[gobie]

It Depends On The Type And Body Mass Of The Fish. I Have A 75 And 3 Fish And Tons Of Lps

 

[wrightme43]

Wow this topic always has many different opinions. Mine are that with a shallow sand bed and proper maintence of the sand bed you will be fine, with even a goodly number of fish. I stir my sand bed frequently, I shiphon the water while stirring. It does remove alot of junk. Here is my take on the situation, I do not believe that a sand grain can become saturated with any thing. It is not carbon, sand has a porus structure yes, but it is covered in a biofilm of bacteria. I can however fill the area between the sand grains with detirus, I can stir and siphon out this junk from my tank. I look at it like this, I have a huge amount of surface area in my sand bed covered in bacteria that are useing waste produts of my fish to make more bacteria that use waste products of my fish. I think that sand is a very viable option for reef tanks. I like the diversity of life in my sand bed. I like the way it looks. I like that the sand is working for me. I have to disagree with the idea that it can become saturated with something, and then just release it all at once and cause some kind of monster algae bloom. I can not see how that would work. Please understand I am not trying to cause a fight here, I just dont see how a bare plastic bottom can in any way provide the diversity of a sand bed. If I have an extra 20,000,000 bacteria per pound of sand in my tank I believe the tank is more able to deal with nutrients. Thats not counting the worms, pods, tiny stars, and snails that call my sand bed home. Just a different view on a complex issue. Steve

 

[idgy]

OK, I understand what you are saying, you have live sand? When you stir up the sand and vac. don't you take out all the good stuff that lives in the live sand?