DSB in a bucket for nitrate control

[seanm001]

I have an isoltated DSB section in my sump and it started growing cyano on the side facing my fuge (due obviously to the light exposure). The cyano grew at significant depth, maybe in the 6-8" range. I've blacked out the side of my fuge so light no longer reaches the DSB, and now the cyano has died off. The problem seems to be that the dead cyano has turned black and the black area is spreading slowly but surely across the DSB. I'm wondering if this black area is ok or if it's bad? Is the cyano somehow rotting and polluting my DSB? Should I turn off the flow through the DSB and give it a stir to release that black stuff? Or just leave it alone?

 

[TheFishMan65]

I think someone is going to ask if it smells like sulfur (rotten eggs). If I understand this from my reading. Then if it smells you will need to replace it. If it doesn't smell you are are alright. Please wait for an expert to respond, but I think they will need this information, I am just throwing in my $0.02 while I ask

 

[seanm001]

I can't smell anything as of right now coming from the tank or the DSB. If it's advisable, I could scoop out some of the black stuff and give that a whiff, but I'd have to dig down more than half the depth of the DSB, so I'm hesitant to disturb it that much unless it's necessary.

 

[bigevill1]

This may be a stupid question, and I feel dumb for even asking it, but do DSBs help with phophates at all?

Also, in the less stupid categories, does it hurt the DSB if you plant mangroves in it? And would there be anything wrong with combining a remote DSB as a frag tank where the frag sit on top of the sand bed?

Right now I setup my 20 long frag tank with about 8 inches of sand and 6 mangroves......

 

[biecacka]

would one 5 gallon bucket be large enough for my 220?
corey

 

[trmiv]

Coming back after being a semi out of the hobby for awhile. Was thinking of doing an rdsb after toying with the idea a few years ago (in this very thread ) . So I thought I'd drag this up from the dead to see after all these years how these rdsb's actually worked for people?

 

[tommer725]

"You can have problems with a deep sandbed, but if you have the right type of CUC and gobies and shrimps that naturally stir the sand then that lessens the bubble problem. My sand does bubble off most of the time. This is do to the fact that a deep sandbed has anarobic areas that converts nitrates to nitrogen gas. The problem that was talked about isl the fact that unstirred sand from a Deep sandbed developes hydrogen sulphide (that rotten egg smell) which is a poison."


I read this and I did not write it. But it states that you really need to have sand sifters. What do you all think?

 

[Reefin' Dude]

This may be a stupid question, and I feel dumb for even asking it, but do DSBs help with phophates at all?

Also, in the less stupid categories, does it hurt the DSB if you plant mangroves in it? And would there be anything wrong with combining a remote DSB as a frag tank where the frag sit on top of the sand bed?

Right now I setup my 20 long frag tank with about 8 inches of sand and 6 mangroves......

it all depends on what you mean by help with phosphates. PO4 binds to calcium carbonate. so the DSB acts like a giant sponge. like any sponge it will eventually need to be cleaned if you plan on maintaining its functionality. there is not an export mechanism of phosphates from a substrate.

you are correct in thinking that true plants can "remove" some phosphates by binding them in their structure, the same as any organism. the problem is that the phosphates are still in the system, they have not actually been exported until the organism is removed. until that point the system still has the same amount of phosphates. there has been some talk of using turtlegrass instead of mangroves. they grow faster than mangroves. both however are limited by the amount of phosphates they will have access to in the substrate. areas immediately adjacent to the root structure.

there needs to be a phosphate export mechanism or a system will just keep becoming more nutrient rich (eutrophic).

G~

 

[tommer725]

so above all the pages of what conversation went on...do we need some types of sifters?

 

[bertoni]

In theory, the animals in a DSB can convert phosphorus into a skimmable form. I don't know of any measurements as to how much actually might be removed that way.

Sand sifters generally will eat all the animals in the sand. That's why they sift it. They aren't required, and I wouldn't have any in the tank if I wanted a live sandbed.

 

[bertoni]

In theory, the animals in a DSB can convert phosphorus into a skimmable form. I don't know of any measurements as to how much actually might be removed that way.

Sand sifters generally will eat all the animals in the sand. That's why they sift it. They aren't required, and I wouldn't have any in the tank if I wanted a live sandbed.

 

[Reefin' Dude]

it all depends on what one means by sifters. the normal benthic inverts that are in a "healthy" substrate are going to be in there anyway. they help in the slow migration of phosphates downward by their "sifting", or going through the grains looking for food.

i agree with bertoni that the larger sifters unfortunately tend to feed on the smaller ones and if the balance of predation is off, then the lack of small benthic inverts can clog up the slow migration of nutrients down through the substrate.

i have not found any evidence in my searches that show that there is any appreciable migration of nutrients out of a substrate. all of the papers i have seen on nutrients with respect to substrate depth all point to nutrients higher in a substrate, than in the surrounding water column, and that it varies significantly with depth.

some interesting reading on substrates.

Variable rates of phosphate uptake by shallow marine . carbonate sediments:
Mechanisms and ecological significance

nutrients and depth. the marine one is a bit deeper than our systems.

Authigenic Sediments

G~

 

[tommer725]

Well this was covered earlier and it was said that in the sand bed there is a gas that forms that when released is poision to a reef, and if you have sifters it will stop that from happening. That is why I heard you need sifters.

 

[Reefin' Dude]

you are thinking about H2S. it is formed when lots of organic material accumulates in areas that have very little access to oxygen.

again it depends on what you consider sifters. the sifters we associate with our systems are surface sifters. they would not really help much in this case and most tend to eat the sifters (those critters which actually live throughout the substrate) that will help the most. these critters will show up in a system anyway. if there is any LR from an established system used in the setup of a system. then there will be benthic inverts in the substrate in short order once the slow migration of phosphates starts.

G~

 

[madean]

So is the drab, the one described earlier in this thread a bad idea? I had mentioned this idea idea, rdsb in a bucket, to a local fish store employee and he said it was debunked. He said that their was a study conducted at university of Davis (he thought it was, but couldn't say for sure) that basically said that nitrates were converted to another form of nitrates that were not detected by the test kits we use in the hobby. Basically saying that a form of nitrates were still present but not showing on a nitrate test. Thus giving us a false reading and making us believe that we were nitrate free, when in actuality we are not.
Can anybody shed some light on this and maybe give a better explanation on this. This thread had a crazy amount of responses and following and then just died. Does the rdsb not really work as described so many years ago? Any info would be great. It seems that this thread sort of died.

 

[Reefin' Dude]

no necessarily. it all depends on how you think that these function. if you are thinking they function like they are said in the beginning of this thread, then they are a bad idea. if you thin that they function like what is talked about in the later part of the thread, then they can have some benefit.

phosphates have been ignored in the beginning when DSB were introduced and through most of their heyday. the thing is that phosphates are absolutely necessary if a DSB were to behave like we were told they would, but the problem is that there was not an export mechanism to counter the slow build up of phosphates. if this is taken into account, then there is no reason not to use a DSB if one understands what maintenance would be needed with the DSB to support the desired trophic level emulated. one must understand the tool before it can be used to its full potential.

i am sure i helped make that clear as mud.

G~

 

[S2minute]

DSB in a bucket for nitrate control

Hi folks, just thought i'd pop in and tell everyone my little story. Recently, i lost nearly all my fish to what i'm thinking was Velvet. The remaining 2 are in Quarantine now for more than a month. So, that being said, i decided that my DSB needed to be changed.
My DSB is avg 6" of the once easy to get South Down playsand from HD. This DSB is in my cryptic/semi-cryptic 150 Gal standard. It has an arch formed out of cvpvc pipe from one end to the other and is covered with LR that has long since gone cryptic and is covered with various species of sponge growth. The DSB is segmented into 12 compartments. I did this with the idea of after 3 years of use, i would then change out 1 compartment each month during a 12 month period. The sides of the DSB are covered in hvy black plastic so it's not exposed to any ambient room light. Each compartment is labled with the change date. This DSB has been through alot and has gone well past it's 3 year mark. This is the 5th year since.
It is for this reason that's it's been through so much that i've decided to change to new sand each month of this year. I wondered if i could just rinse well and reuse the old sand but, i was concerned with the thought that toxic metals may have been building up in the DSB. I not sure it be worth the effort to clean and reuse. However i wish to tell you of what i did observe with the current DSB.
First, i've NEVER preformed any maint on it and this is why. I simply never had to. This tank is part of a 4 tank multi-system based on Steve Tyrees Environmental Gradient System. Once in a while i would peel back portions of the black plastic and observe. At times i'd also use my little magnifying glass i always have hanging around to watch. The sand surface is always smooth and loose. Sometimes, i'll see little trails here and there or a pod crawling about. The LR deposits large amounts of Detritus on the DSB but, it NEVER accumulates. I've never seen a black area indicating an H2S build up either.
The most fascinating thing is the amount of pods and worms living within the first 3/4" of the DSB surface and extending down to as much as 3" in some cases. These critters are pulling all the detritus below the surface and eating it. So i break out the magnifying glass and get a close look. I see them living in long horizontal borrows or tubes that lace the substrate making contact with the top every inch or two. It looks like they pull the detritus into their burrows and eat it. Recently, i had been feeding the system directly with 3 species of live Phyto that i culture. However, that gave me a nasty Bryopsis outbreak that really is ****ing me off .
If my current DSB had not gone through all i knew it did over the past 5 years, i'd just leave it alone indefinitely. The only time i noticed a rise in NO3 was when i was feeding live Phyto. Even then it was never above 2ppm. I believe the DSB works very well under NORMAL condictions. I say this because in it's 2nd year, the current DSB delt with a near system crash because i had been distracted by a serious event in life that almost made me stop the hobby all together. SO, because of these things, i will replace with new SD sand over this year and monitor it's progress. I believe you can maintain a DSB for a very long time. You can see pics of the DSB setup with the black plastic and date marks on my profile if you like though some of the pics are pretty rough. Any input and advice is very welcome! Take care! :wavehand:

 

[The Plummer]

Allow me to resurrect this thread from the dead, simply because I think this is one of the BEST additions to the reef keeping hobby I've ever encountered. Many can benefit from it.

I got out of the hobby nearly 20 years ago, due to the frustration of nitrate export and I found out just how ineffective water changes for nitrate and phosphate really are. The reality of water changes to export those nasties, either in the name of "maintenance" or as an attempt to remedy an emergency, are really about as effective as doing a rain dance in front of your display, hoping to change the reality that your technology is inadequate to perform the task at hand.

That being said, let me tell what I've done to achieve such a high level of confidence in this technology.

Less than three months ago, I decided to set up my old 55 gal tempered glass aquarium, so it's not possible to make it Reef Ready, like I always wanted it to be. Actually, this turned out to be a blessing in disguise. Due to that fact, I decided to recycle my old HOB wet/dry filter, rather than spend money on a new skimmer box setup if this experiment didn't work out. I am able to use the heater box, the prefilter ( this is KEY to the simplicity of the implementation of the RSDB), the carbon chamber, the protein skimmer (I'm not totally satisfied with this device, but will address it in the near future), and the (now empty wet/dry drip filter box.

Because I have pre-filtered water, as well as protein skimmed water at the same height as my aquarium, I have been able to install the RSDB and utilize gravity to my advantage. All I had to do, was ensure that the lid on the bucket is higher than the level of my sump water to avoid pressure issues with the lid seal. I chose not to drill holes in the sides of the bucket, but rather installed the bulkheads in the lid, opposite to each other. Both bulkheads are 3/4" as the size of the output is irrelevant in a total gravity system, such as this. Inside the bucket, I screwed a 90 degree elbow into the bulkhead and glued a 1"x1"x3/4" tee on that, to ensure total dispersion and aid in the prevention of a sandstorm.

60 lbs of absolutely the finest sugar oolitic aragonite "dry" sand, topped with 5 lbs of aragonite gravel to further inhibit the possibility of a sand storm. The filtered water then drops into a sump, to be returned back to the display.

Now for the results, once the ammonia spike was finished (about six weeks) the aquarium was ready, absolutely zero ammonia, nitrite, nitrate. PH is steady at 8.2, no matter what I livestock I add to the display.

The only issue now is aggressive phosphate export, to prevent the substrate from soaking up phosphate, and avoid the ticking time bomb that DSB's have the potential to become. But that is another technology to address elsewhere.

My point to all this is, when carefully thought out, this system IS the best thing going IMHO, with regards to nitrogen cycle that I've ever seen.

BTW, I've not needed to perform ANY of that "maintenance" that I mentioned earlier. Not to say that water changes aren't necessary, but if your doing them to reduce nitrates, rethink your technology.

 

[Reefin' Dude]

if you think water changes is all about removing water, then yes, you are correct. they do very little to export nitrates and phosphates. if one uses water changes as a means of removing detritus and other solid wastes, then the siphon is the best way to remove nitrates and phosphates. get the detritus out before it rots, then you will not have an inorganic nutrient problem.

G~

 

[The Plummer]

I agree completely, though siphoning is not necessarily the only way to remove such waste. I'm going to try an experiment here, maybe you could help me work out the details.

My hypothesis is that the hobby industry is hell bent on sales, whether or not the sale is necessary. I'm not a "latest, greatest, gadget kind of guy". I believe the industry (motivated purely by sales) is propagating the myth that "regular water changes are essential. That's just one aspect of my philosophy.

I believe that the market driven "sheep" are being led down a road of unnecessary effort and expense. I believe that with a well tuned Eco system, water changes can be greatly reduced if not eliminated.

The RDSB is merely step one. I feel this is step one, while ammonia and nitrites are deadly in small amounts, the next most deadly is nitrates, but the REAL ticking time bomb is the dreaded phosphate exportation issue.

That leads me to step two. To my limited knowledge, the only ways to reduce or eliminate phosphate is either don't put any in the system and/or physically remove them from the system.

If your not effectively removing phosphate from your system, you may be lulled into a false sense of security as the phosphate sponge (all substrate) in your system will eventually become "full" and that's when the "time bomb" starts to wind downtown the final seconds, before a catastrophic event happens. I.E. Tank crash.

So I believe there are certain "steps" to be taken to reduce, or eliminate the impending doom.

My hypotheses at this time is as follows:

1. Good pre-filter, immediately after the water exits the display tank.

I'm currently using three stages of filter floss and one stage of filter sponge in a gravity feed fashion, followed by a simple air stone protein skimmer (plans are to upgrade this to some type of in-line skimmer, upstream of the RDSB. About 60% of my water flow actually gets to the RDSB, the remaining is piped directly to the sump. All the water gets pre filtered and all the water has the opportunity to be skimmed, though I don't have any idea what percentage that is yet.

Step 2. Good in tank flow, to keep the nasties suspended for as long as possible, to give the pre filter a chance to catch it.

Step 3. USA a small hand held power head to blow off the rock work and loose detritus back into the water column to give the pre filter another shot at catching it.

Step 4. I have a small HOB fresh water filter that I'm going to hang on the front of my DT and attach a short piece of tubing and my gravel vacuum to clean the substrate without eliminating the water.

Step 5. Plant live plants that aggressively take up phosphates for re-feeding and removal.

Step 6. Maintain trace element, calcium, & magnesium levels, by using available products. I'm currently using Kent Reef Essentials and Aquavitro calcification to maintain the levels.

Now, I'm so radical in this concept, I'm not even using do/di water. Nope, just plain old well water without any filtration or additives.

What I do have as an advantage is that my well water comes from a underground river that follows the Missouri River and is in the top 3% most pure water in the world. There are issues with extreme hardness though, but I figure free calcium is free calcium. The well water does contain phosphates also, but again a properly designed export system can mitigate that issue also.

My questions to you are as follows, what particular species of plant life would be both most aggressive in phosphate removal, as well as easy to implement and export. Any thoughts there?

How about plant life for re-feeding to reduce more introduction of new phosphate?

Are there any aspects of my hypotheses that I'm not taking into account?

Your thoughts are welcome, but don't flame me for trying to think too far out of the box, I can always back up, if necessary.