DSB in a bucket for nitrate control

[Paul B]

Paul_b- actually cleans his substrate regularly. I believe he calls them Typhoons.

Yes he does. He told me so. But not for the same reasons DSBs crash or don't last long or whatever the problems are. Me, or "he" has to create typhoons because he, or "me" uses a reverse UG filter which utilizes gravel. The "cleaning" is to ensure the gravel does not clog as I need circulation throughout the entire bed. My system depends on some detritus to slow down the water flow and create areas where bacteria (and pods) will feel welcome. I don't think of detritus as a bad thing, just an inert substance that tends to clog my RUGF.
Sorry for the intrusion. Please continue with your fascinating discussion. :wave:

 

[CuzzA]

I'd like to see a video of one of these PaulB typhoons he speaks of. Does he blast water through the rugf?

 

[Paul B]

I don't have a video of it so squint your eyes and move your head back and forth to simulate movement. Also put on some ocean sounds from your I Pod

 

[Rybren]

Pual, every time I squint at your picture and move my head side to side, I start to see visions of SuperModels. Am I doing something wrong?

 

[dkeller_nc]

Pual, every time I squint at your picture and move my head side to side, I start to see visions of SuperModels. Am I doing something wrong?

Sounds like you're doing something "right" to me! Can I have some of whatever you're having?

 

[Rybren]

Just a little vodka dosing but not to the tank. ☺

 

[Paul B]

I start to see visions of SuperModels. Am I doing something wrong?

exactly. perfectly OK

 

[Dan_P]

Yes he does. He told me so. But not for the same reasons DSBs crash or don't last long or whatever the problems are. Me, or "he" has to create typhoons because he, or "me" uses a reverse UG filter which utilizes gravel. The "cleaning" is to ensure the gravel does not clog as I need circulation throughout the entire bed. My system depends on some detritus to slow down the water flow and create areas where bacteria (and pods) will feel welcome. I don't think of detritus as a bad thing, just an inert substance that tends to clog my RUGF.
Sorry for the intrusion. Please continue with your fascinating discussion. :wave:

Paul is your tank's substrate aragonite? How coarse would say it is, mm size particles?

 

[CStrickland]

Paul is your tank's substrate aragonite? How coarse would say it is, mm size particles?

Paul uses dolomite, rugf's don't work on little particles

 

[Dan_P]

So where does nitrate fit into all this? Nitrates are an electron acceptor used during respiration of carbon compounds in low oxygen environments. The nitrogen in nitrates are used in place of the more energetically favorable oxygen. What happens is that electrons freed during breaking of carbon bonds plus hydrogen combine with oxygen and nitrogen atoms of the nitrate molecule to form N2 and H2O. (See Denitrification).

Why does that work better in a Bucket DSB compared to in the rest of the tank? The conversion of ammonia to nitrate occurs on every surface of the tank. In a Bucket DSB, the bacteria responsible for converting ammonia into nitrate are now in close proximity to the bacteria that are using the nitrates for anoxic respiration. , the nitrates have just as likely a chance of diffusing up out of the top of the sand as it does down to where the bacteria are actively converting it into nitrogen gas.

I like the sand bucket idea and will try it someday. I wanted to point out a possible flaw in the arguement above.

Whether the substrate is in the bucket or at the bottom of the aquarium, the statement "ammonia is oxidized on all surfaces" can be true for both systems. Also, I am not aware of any evidence that substrate in a bucket is any more effective than the bottom of the tank. The fact it can be changed out much more easily than substrate in the display tank is a plus.

How is this different from inside the display?In the display, the nitrates released by the bacteria gets released into the water column and therefore is readily accessible to the algae for growth. By contrast, any nitrates that travel lower into the sand bed will be broken down and released into the air and can no longer contribute to biomass growth.

I think this might be a mistake. The fluid dynamics around substrate in a bucket and the display tank do not to seem to be all that different. Why would substate in the tank spew out nitrates and wouldn't in a bucket.

The two quoted points are unnecessary to explain the success of substrate in a bucket biofilters.

 

[Paul B]

Paul uses dolomite, rugf's don't work on little particles

Exactimundo

You can see my dolomite here behind the blurry pipefish. Aragonite wasn't invented when I started the tank.

 

[RocketEngineer]

Whether the substrate is in the bucket or at the bottom of the aquarium, the statement "ammonia is oxidized on all surfaces" can be true for both systems. Also, I am not aware of any evidence that substrate in a bucket is any more effective than the bottom of the tank. The fact it can be changed out much more easily than substrate in the display tank is a plus.

The difference is depth. The bacteria all over the tank are oxidizing ammonia. The bacteria in the sand are just as effective as those say on the glass or on the rock. The difference is that the bacteria in the bucket are close to other bacteria in a lower oxygen environment. That proximity means that some of the nitrates are migrating towards that anoxic environment instead of just getting released into the tank. Not all, but enough.

I think this might be a mistake. The fluid dynamics around substrate in a bucket and the display tank do not to seem to be all that different. Why would substate in the tank spew out nitrates and wouldn't in a bucket.

The two quoted points are unnecessary to explain the success of substrate in a bucket biofilters.

Actually, it does. The difference is that nitrates diffusing down in the display run into the bottom of the tank, nitrates diffusing down in the bucket are consumed by the bacteria in the anoxic zone at the very bottom of the bucket.

BTW, the reasons UGFs were first implemented in aquariums was for nitrification of ammonia. Bioballs serve the same function. The issue we run into is that both of these filters halt the nitrogen cycle at nitrates. By contrast, a Bucket DSB is able to close that cycle and convert the nitrates into nitrogen gas which then escapes the tank.

 

[Dan_P]

The difference is depth. The bacteria all over the tank are oxidizing ammonia. The bacteria in the sand are just as effective as those say on the glass or on the rock. The difference is that the bacteria in the bucket are close to other bacteria in a lower oxygen environment. That proximity means that some of the nitrates are migrating towards that anoxic environment instead of just getting released into the tank. Not all, but enough.



Actually, it does. The difference is that nitrates diffusing down in the display run into the bottom of the tank, nitrates diffusing down in the bucket are consumed by the bacteria in the anoxic zone at the very bottom of the bucket.

BTW, the reasons UGFs were first implemented in aquariums was for nitrification of ammonia. Bioballs serve the same function. The issue we run into is that both of these filters halt the nitrogen cycle at nitrates. By contrast, a Bucket DSB is able to close that cycle and convert the nitrates into nitrogen gas which then escapes the tank.

If this were true, my two inch silica sand bed would not be deep enough to make nitrates undetectable. I have begun a study of the substrate pore water and all I detect at the bottom of the sand bed is ammonia and phosphate (both also undetectable in the overlaying water). No nitrates are present. No nitrates in the water either. Proposition: denitrification occurs in shallow beds. But this is really old news. Toonen's study of plenums and different sand bed depths reported in Advanced Aquarist also gives hints that denitrification is occurring in shallow beds by the fact that the amount of nitrate accumulating in the water was less than the ammonia added.

Studies of marine sediment show anoxic conditions are reached in cm not inches. Microelectrode oxygen probes show that even at several mm, anoxic conditions can exist. This is relevant because water flow in substrates in aquariums, except Paul B's, is likely to be much less than found in the ocean. Sufficiently anoxic conditions are very likely to exist in shallow aquarium substrates. The fact that some systems have high nitrates is more likely due the bioload exceeding the denitrification capacity of the substrate rather than nitrification not occurring.

Adding a bucket of sand to expand the surface area of the substrate is bright idea which I plan to try.

 

[RocketEngineer]

I agree that these processes are going on all over the tank. I think the reason folks see the drastic reduction in nitrates after adding a bucket DSB is that we are providing that additional area where the sand isn't being disturbed and doesn't have any lighting which may be the ideal conditions these bacteria need. And because of that, its enough area/volume for the denitrification process to exceeding the nitrification process. In doing so the nitrate levels in the tank drop until the two go back to being in equilibrium.

 

[Swope2bc]

I find this discussion to be fascinating and given the years of successful reduction provided by the RDSB it would definitely seem that even if the remote bed does in fact accumulate P the rate at which it increases in fractional compared to the average DSB in DT. I have no first hand experience in this but base my hypothesis on the observations made by others, so take it as it is, but none-the-less, a very interesting discussion.

 

[Newreeflady]

Longest thread of all time! Please link to optimal conditions for plumbing (height of sand, distance above sand for input water, bulkhead size and flow rate of input water, how to keep water from disturbing sand... ) better yet, plumbing photos? Thanks all I'm thinking of using this because I was successful years ago with an in-tank dsb until it got "full", oh if one could swap it! I find the vodka method too hands on for me so this might fit the bill with gfo and phosban.

Anyone using in a skimmerless system? I hate skimmer noise. Cheers!

 

[ReefInterest]

Bringing this back from the dead (because someone linked to it in another post).

I like the idea of a 5 gallon buck with sand plumbed into the system. Once a year, plumb a second bucket into the system, wait a month and remove the first, dispose of sand, repeat the next year.

Thoughts?

 

[Jade5051]

I've seen a few setups where ppl are using modular DSBs. They take about 4-6 plastic 1 gallon buckets and fill them with sand and set them in the sump/refugium. Every few months they remove 2 of the buckets rinse the sand and then put it back. They rotate through cleaning the buckets and don't lose the effectiveness of the DSB.

Pros I see are you can reuse the sand and avoid old tank syndrome.

Cons I see are it takes up space.

 

[davidwillis]

It has been 18 years since this first started, and 7 years since the last post. Is there any updated information?
Here are a few questions I have. (sorry I have not read the entire thread). I did a search an started reading in the old backup with two threads... I am only part way through. It is going to take a while, so I wanted to skip to the end and see if it was still something people were using.

1- Is there a basic guideline as to how much one bucket will filter? I saw that one 55 gallon tank full would filter a 2,000 gallon... But is there a comparison like it will filter nitrates comparably to a liter of bio pellets in a reactor?
2- If you run water through a 50 micron filter before going into the sand bed, do you need to worry about flow? Since it sounds like the main idea is to keep things particles to settle
3- Any long term maintenance? If you have multiple buckets, should you rinse one at a time every few years?
4- This seems like a very good method for removing nitrates. Why is it not more popular?
5- has anyone been using this for 18 years?

Before I found this thread, I posted a question in another forum saying I was thinking of using a remote deep sand bed, and nobody thought it was a good idea, and just suggested I feed less, or use biopellets or an ATS. To me this seems much cheaper, simpler, and would work better....

 

[jason2459]

Well, since this thread started @Paul B has made it past the half century mark with a RUGF...

I've been running a RUGF in my tank or sump since 2009..