........Question on Deep Sand Bed............

[Xgame2k]

Lets say I get a Deep Sand Bed. Do I need to do anything to it in the long run? I hear many things so im not sure. I have heard that you need to replace it when it gets full and so on, not to vacuum it, add starfish, crabs,,,,and so on.... What is true?

[Xgame2k]

???

[alaska clowns]

I don't know much.....well, anything....about DSB's, but I stumbled across this thread on RC while doing research one day. It's how to do a remote DSB in a bucket, and it sounds like it's worth a try; in fact, I just put some bulkheads in my 5 gallon bucket, and I'm going to hook it up when I get my sump in place. It's an interesting read, anyhow, hope you find it helpful!
http://reefcentral.com/forums/showth...t=595109&pp=25

[Xgame2k]

that still doesnt answer any of my questions, but it would be cool if i wasn't going to put sand in my tank.

[ChadTheSpike]

Here are my thoughts on DSBs (I am a huge believer and have used them on all of my tanks for about the last 8 years, my longest running sandbed was about 5 years).
Stuff that goes in it: I dont add anything to my tanks that depletes the sandbed of microfauna (like sand-sifting stars or gobies). I think they eat too many of the beneficial pods and worms and such that make DSBs useful, crabs are ok in the DT but not a fuge. If your tank is large enough (I would say >2 square feet of accessible sand surface) a cucumber is beneficial.
Flow: higher than most think, at least 10x turnover, in a fuge usually flow is not high enough to maintain a DSB unless specific action is taken to increase it. Flow should be high enough that stuff doesnt easily settle. A healthy sandbed should 'look' clean, and flow is a large part of this.
Need to replace: Its not necessary, a healthy DSB processes waste, it doesnt 'fill up', although the sand does have a half-life as it dissolves into the water providing buffering and trace elements to the water chemistry. As such, the sand itself needs to be periodically added to, I add enough to make the depth always be greater than 6-7 inches. I do this by filling quart sized ziplocks with washed sand, then putting the entire bag into my tank and cutting it open, it minimizes the mess of doing so. I add some sand every few months and never more than about 1/4 at a time stirred into the top little bit of the existing bed.

[Xgame2k]

Thank you. This is what i was hoping for. So it will be fine to add new sand every couple of months even when it gets passed the recommended 4-6 inch maximum mark? I have a 450 gallon display tank with 120 gallon sump and was thinking of putting a deep sand bed in both (dead sand and a couple cups of live).

[billdogg]

I have a 150 DT with less than an inch, and a 120 fuge with ~6" (seperate 50g sump.

+1 on what was posted above! - but I use a long piece of 3"pvc to get the sand to the bottom without a sandstorm

[Xgame2k]

Originally Posted by Xgame2k

Thank you. This is what i was hoping for. So it will be fine to add new sand every couple of months even when it gets passed the recommended 4-6 inch maximum mark? I have a 450 gallon display tank with 120 gallon sump and was thinking of putting a deep sand bed in both (dead sand and a couple cups of live).

Can anyone answer this?

[Playa-1]

I would suggest you do lots of research before taking action. There are pros and cons to a DSB that you need to be aware of. In a tank of that size you will have lots to loose if something goes wrong. I'm not saying a DSB is a bad Idea but I'm just encouraging you to be well informed up front.

[Xgame2k]

that is why i posted this. There might be a couple pieces of live rock in the tank but most in the sump and will have 2 small sharks in it so flow will be as high as i can get it.

[ChadTheSpike]

+1 to Playa-1 on knowing for sure what you are getting into.

I personally would do it with a large tank (like your 450 gal), although I would increase the sand depth in the DT to never go <8 inches. Although I cant say that I have a technical reason for this, it would just make me feel better You never know when a large tang or something will knock a powerhead down to blow directly into your sand bed or something like that. In all of my smaller DTs I have gone with a really shallow sand bed (barely covering the glass) because it is easy for me to keep it clean, and I dont have to worry about me or my equipment seriously disturbuing the DSB (Im not worried about the livestock doing it).

You would be fine adding sand every few months as it dissolves, just dont go crazy with it and bury a live sand bed with 3 inches of new sand, all the little critters are down there and need some love too!

BTW, I like the idea of dumping sand down PVC pipes to prevent the sandstorm.

[ChadTheSpike]

Originally Posted by Xgame2k

that is why i posted this. There might be a couple pieces of live rock in the tank but most in the sump and will have 2 small sharks in it so flow will be as high as i can get it.

Its funny you mention the sharks, I was going to use an example of a shark tank having a very deep DSB (>12 inches) with high flow in the tank. If you have seen on of these setups in the past the sand is absolutely pristine and usually very deep. It is an excellent example of a live sandbed in action.

[Xgame2k]

So i should be fine if i use 4 inches of sugar sized aragonite sand to start? What would I need to do once it gets over 8 inches?

Thanx.

[jenglish]

Originally Posted by ChadTheSpike

Here are my thoughts on DSBs (I am a huge believer and have used them on all of my tanks for about the last 8 years, my longest running sandbed was about 5 years).
Stuff that goes in it: I dont add anything to my tanks that depletes the sandbed of microfauna (like sand-sifting stars or gobies). I think they eat too many of the beneficial pods and worms and such that make DSBs useful, crabs are ok in the DT but not a fuge. If your tank is large enough (I would say >2 square feet of accessible sand surface) a cucumber is beneficial.
Flow: higher than most think, at least 10x turnover, in a fuge usually flow is not high enough to maintain a DSB unless specific action is taken to increase it. Flow should be high enough that stuff doesnt easily settle. A healthy sandbed should 'look' clean, and flow is a large part of this.
Need to replace: Its not necessary, a healthy DSB processes waste, it doesnt 'fill up', although the sand does have a half-life as it dissolves into the water providing buffering and trace elements to the water chemistry. As such, the sand itself needs to be periodically added to, I add enough to make the depth always be greater than 6-7 inches. I do this by filling quart sized ziplocks with washed sand, then putting the entire bag into my tank and cutting it open, it minimizes the mess of doing so. I add some sand every few months and never more than about 1/4 at a time stirred into the top little bit of the existing bed.

Sand beds are made of calcium carbonate and will bind PO4 just like live rock. Good filtration and flow should prevent this but if you get a whole sand bed loaded with PO4, then it will need replaced. A sand bed can process nitrogen, but not phosphate. I recommend frequent siphoning to help prevent detritus from building up.

[Xgame2k]

And how would one know when to replace the entire bed?

[jenglish]

Originally Posted by Xgame2k

And how would one know when to replace the entire bed?

Algae problems generally.

[Xgame2k]

Is that it, other than the death of my fish?

[jenglish]

A dsb full of PO4 is not going to kill your fish, just feed unsightly algae

[Xgame2k]

So you only need to replace it if you cant stand the algae?

If that is it, i have nothing to worry about.

And i have also heard people use this: PO4-Minus - Phosphate Reducer

[Xgame2k]

..?

[uncleof6]

Originally Posted by alaska clowns

I don't know much.....well, anything....about DSB's, but I stumbled across this thread on RC while doing research one day. It's how to do a remote DSB in a bucket, and it sounds like it's worth a try; in fact, I just put some bulkheads in my 5 gallon bucket, and I'm going to hook it up when I get my sump in place. It's an interesting read, anyhow, hope you find it helpful!
http://reefcentral.com/forums/showth...t=595109&pp=25

It needs to be noted that a bucket DSB is a completely different animal (pun intended) than an in tank DSB. The bucket DSB is strictly a bacteria based "filter", solely for the purpose of processing ammonia > nitrite > nitrate ~ free nitrogen gas. The in tank DSB is an animal based system. As well as providing the basic bacterial processes above, it provides a more comprehensive processing of organic solids, using them as food sources to fuel a highly bio diverse population within the sandbed as well as scavangers on the sandbed surface. I am not picking on you at all, because you stated clearly that your knowledge of sand beds is limited. The two methodologies need to be kept seperate.

Jim

[uncleof6]

Originally Posted by Xgame2k

So you only need to replace it if you cant stand the algae?

If that is it, i have nothing to worry about.

And i have also heard people use this: PO4-Minus - Phosphate Reducer

Algae growth on the surface of a sand bed, can be due to a couple of things. The most common is inadequate water movement over the surface of the sand bed. And is not related to a problem with the sand bed itself. Generally this would be a Diatom bloom. A well set up, properly seeded, and matured sand bed will have a surface that is clean and "white." The band of algal growth visible on the glass surface in the area of the sand bed, is only on the glass surface, not throughout the sand bed, and is caused by ambient light around the tank.

Most if not all problems, purportedly inherent, with DSB's, are not problems inherent with DSB's, but rather inherent with a lack of understanding and knowledge concerning the how and why of DSB's and/or plenum type systems.

Though the setup of a DSB is simple and straightforward, and relatively inexpensive, the seeding and maturing of it (the how of it) is a bit more involved, than adding a couple cups of "live sand" (seeding). The maturing of it requires encouraging population growth with feeding, and requires patience because the sand bed needs to be matured prior to adding predators (including some species of CUC members).

Long term maintenance of a DSB is rather straightforward too, and involves a knowledge of "why:" Animal activity in the sand bed, population fluctuations, and lower pH values-- in the lower levels of the sand bed.

Depth of sand bed 4" - 6." Maintained at that depth, adding sand IF the depth decreases due to the lower pH values in the lower levels of the sand bed. (The small grain size, .2mm - .050mm, will dissolve more readily)

A decrease in effectiveness of the sand bed is usually due to a decrease in population (population fluctuation.) Add more critters. The diversity in a well fed sand bed can easily exceed 200 species. Far greater than the diversity of life it is intended to maintain in the tank. (corals, fish, etc.) Another consideration with this population level, is it greatly increases the BOD (Biological Oxygen Demand) of the system, and higher flow rates, (aeration) of the water is necessary.

The activity of the animals in this highly diverse and populated sand bed, will greatly reduce-- or eliminate, the build up of toxic gas pockets, and prevent "solidification" of the substrate sometimes referred to as inherent with sand beds. (This latter condition is now more associated with bacterial secretions, rather than the substrate dissolving)

Such a sand bed can process the wastes from feeding the tank to the maximum capactiy of the sand bed, without an increase in NO3 or PO4, and is self maintaining except as noted above.

Regards,

Jim

[Xgame2k]

Can that be put into a simple "to do" form?

Thanx,
Chris

[ChadTheSpike]

Jim is far more eloquent than I am and much better at explaining things

But Ill take a stab at your to do list

Setup (assuming a new system): Add all the rinsed sand to the tank to the desired depth, like I said my preference is >8 inches in DT and >6 in a fuge, the reason is is my preference only and I have had success with it. Add some seeding LS and LR, my preference here is from a few different sources going for maximum diversity.
Let the setup mature for AT LEAST 6 months prior to adding anything but turbo snails to the tank. I do 'feed' the tank during this timeframe with a variety of things including mysis, dry foods, phytoplankton and whatever I have around. I have also cultured rotifers for a startup, but Im not sure if it helped, mostly it made me happy to do it. (and I was testing my rotifer culture method without something to feed them to, so I added them to my tank)
I also use this period of time to start macro-algae growth (which is my way of winning the phosphate battle).
After the 6 month fallow period, I move forward with my setup and add other things to the tank.
Maintenance, periodically add a little bit of sand as it dissolves. I do this a few times a year and only add a qt. bag full at a time. I have a mark in a couple of places on my glass so I can monitor this.

[jenglish]

The points Jim raises above are probably the dominant thinking on DSBs that largely trace themselves back to Dr. Ron Shimek. Although I have nothing agains Dr. Shimek I believe his methods are flawed and that maintaining a bed as is described is the reason DSBs crash. We know hypoxic areas house the functional anaerobes that can process NO3 to N2 which can then leave the aquarium as a gas. PO4 has no known means of escape that I have known and will simply bind to the calcium carbonate until all sand has reached capacity. Biodiversity is important to break down things but they are not magical and cannot "process" materials into nothingness. Regular deep siphoning removes organic matter (both in the form of detritus and the sand bed critters themselves) as well as helps to prevent the anoxic conditions in which true anaerobes will produce hydrogen sulfide. These cleanings should be in sections though so as not to remove too much of the population of beneficial organisms in the sand bed.