# Flow Through DSB



## bioload (Oct 20, 2009)

Hi all,

I've recently started a new tank that is about 6 weeks old. This is a brief summary of the tank to date:

Volume - 75gal
Rock - 20lbs live 30lbs dry
Substrate - None
Livestock - 2 Clowns, a Tang and a pair of Coral Banded Shrimp
Filtration - Marineland Emperor 400 BioWheel Filter
Water changes - None to date

The tank has been through it's initial ammonia and nitrite rise and fall with nitrate now being my primary focus, which I would like to be able to control and better understand before I start adding any corals to the tank.

I looked near and far for information regarding Natural Nitrate reduction......... just when you thought you had enough information on the nitrogen cycle.

The Aquarium Nitrogen Cycle

What is the Nitrogen Cycle

Nitrosomonas

Nitrosomonas

Nitrifying Bacteria Facts

Nitrobacter

What does a Bio filter and a Denitrification filter do?

Anaerobic Respiration

Anaerobic wastewater treatment reviewed

Advanced Wastewater Treatment

Wastewater Management Fact Sheet - Denitrifying Filters

Denitrification - Advanced Wastewater Treatment Plant

Denitrification

Denitrification Filter

Wastewater Treatment with Methanol Denitrification

Deep Bed Denitrification Filters Play Role in Improved Wastewater Quality 

Investigation into Methanol as a Carbon Source for Denitrification 

Vodka Dosing...Distilled!

Aqua Medic Nitratereductor

Nitrates in Marine Aquarium Systems

FAQs on Marine Water Quality involving Nitrates 

Biological Filtration

Nutrient Control and Export: Ways to Increase Water Quality and Eliminate Nuisance Algae in Marine Aquaria

An Introduction to Deep Sand Beds

Hourly and Daily Variation of Sediment Redox Potential in Tidal Wetlands Sediment

Effect of Alternate Aerobic and Anaerobic Conditions on Redox Potential

The Food of Reefs, Part 6: Particulate Organic Matter

Hydrogen Sulfide and the Reef Aquarium

ORP and the Reef Aquarium

In my search to gain a better understanding of the process, I thought this may be a good opportunity to look at nitrate specifically and it's removal since my tank is in it's early stages. The articles above raised as many questions for me as they answered.

That said, I would like to set up a remote deep sand bed and monitor/document specifically its effect on nitrate in my system. Based on what I've read results have been mixed.....surprised? My nitrate reading currently are 80-100 API test kit (any recommendations on test kits/monitors would be appreciated as well).

The first thing I would like to know is how long would it generally take for NNR to occur in live rock, so that any observed reduction can be attributed directly to the RDSB. If I were to add a RDSB right now, and I noticed a reduction in nitrates, would it be safe to assume that the reduction was due to the addition of the DSB, or was it some other process that was happening within the rock that I was not aware of.

Secondly, and more important, I would like to know how the flow within a DSB would effect NNR. Has anyone done any trials using a flow through RDSB, or any studies regarding the flow.

Any feedback on the subject would also be great. Hope to have the RDSB in place soon and interested in seeing what happens.

P.S. links are always appreicated (and always read......eventually).


----------



## bioload (Oct 20, 2009)

Where to start?......I guess the first question that I have is, does a deep sand bed remove nitrates. I've seen many applications of sand which include substrates within the display tank, partitioned in a refugium, and even contained remotely in a bucket. However, I've only seen anecdotal evidence of its effects in an aquarium. Below is a DSB that I'm currently setting up in order to measure specifically the effect a DSB would have on nitrate in my tank.










Let me know if there are any changes that I should make or things to consider regarding this approach. Other system details have been listed above and will not change.


----------



## cablemike (Jan 7, 2009)

i have a 4" deep dsb is my refrugium. my first chamber of the sump flows into it via a baffle from the bottom of the dsb but to be honest im not sure it works.. maybe it does as my chaeto had hardly grown in over a year. my nitrates have never gone above 20ppm. mine does not have direct flow like yours but as i said the opening on my baffle is at the bottom so current has to push through the sand to enter that chamber. though my fuge walls are always covered in cyano i have none in my display.. im running two 26w 6700k cfls for lighting in there also.


----------



## bioload (Oct 20, 2009)

Now that the playoffs are over.....congrats to the folks in the windy city, I've had a chance to get everything together.

I've set up the bed to overflow back into the tank which shouldn't affect what I'm looking for, and as indicated more representative of a typical RDSB type set up. In addition I also realized that the 5 gallon tank only had one drain, and if that should get blocked....well you know.

Here are the first few pics....sand will be added later.









From the front









Closeup of the drain









Overflow and drain









Drip control and Return to tank









Where samples will be taken


----------



## bioload (Oct 20, 2009)

DAY 0

Sand Added this afternoon









Particle Size - Not sugar fine sand but the what I have available at the moment. If I don't get any positive NNR I may have to replace. Will also demonstrate how much impact particle size has regarding NNR.









Starting Nitrate Tests









ORP (DSB) = 300mV (dropped to 180mV within 20min of adding sand)
pH (DSB) = 8.00
Drip rate = 0.67 drops/min


----------



## bioload (Oct 20, 2009)

*i have a 4" deep dsb is my refrugium. my first chamber of the sump flows into it via a baffle from the bottom of the dsb but to be honest im not sure it works...* - I'm not sure any DSB works, but I guess I'll find out soon. It's hard to say what impact any one thing has on a tank when we have soooo many variables in play, skimmers, feeding, water changes, liverock, algae. Since my tank is fairly basic (no skimmer, no water changes, not lights (just ambient)) I thought I'd give this a try to see what happens.


----------



## bioload (Oct 20, 2009)

Day 1










ORP (DSB) = 270mV +/- 10mV 
pH (DSB) = 7.29
Drip rate = 0.83 drops/sec

Notes: ORP gradually climbed back up from the initial drop when sand was added. Not sure why this is but I'm thinking may have something to due with flushing out whatever may have been in the sand. Sand was rinsed and stored in a bucket for several week before use.


----------



## bioload (Oct 20, 2009)

Some more intersting links:

Dissolved Oxygen

Oxygen (O) and water

Water deaeration

LOW OXYGEN AND POND AERATION

Dissolved Oxygen and Aquatic Primary Productivity

Autotrophic Biological Denitrification with Elemental Sulfur or Hydrogen for Complete Removal of Nitrate-Nitrogen from a Septic System Wastewater


----------



## bioload (Oct 20, 2009)

Flow Diagram:


----------



## Cypher (Apr 15, 2006)

Hi there,

I'm no expert but I thought I've read in a few places that a DSB needs to use oolithic sand - fine sugar grained sized. Your current set up with crushed coral sand is more like a passive calcium reactor than a DSB, IMO. Again, I'm no expert so I could be mostly or all wrong lol.

Otherwise, I think your setup and experiment are really cool!


----------



## bioload (Oct 20, 2009)

Sugar fine sand is recommended for the set up of a DSB. However, I had this on hand and I figured I'd give it a try. The CC was screened to remove the larger particles. The remaining was less than 1.0mm in size.

Would be interesting to see how critical the particle size really is. If no NNR occurs I will swap out the CC and start over with the sugar fine.


----------



## bioload (Oct 20, 2009)

No Nitrate tests tonight. Did one earlier in day, and I'm beginning to get the impression that this may take a while.

ORP: 187mV
pH: 7.19
Drip Rate: 0.8 drops/sec


----------



## Chris S (Dec 19, 2007)

The particle size is going to play a fairly substantial role, as you need a large section of the sand to be anaerobic. With that size substate, you are not going to see the same results.

I'm interested to see the results nonetheless. Over time, with a build up of debris etc. your substrate should become anaerobic (or moreso).


----------



## bioload (Oct 20, 2009)

When I chaecked the tank this morning I noticed something strange. There was a increase in the ORP and pH readings which were significantly higher than the night before. Did not get a chance to check the drip rate but it seems to be unchanged.

ORP: 291mV
pH: 7.81

Not sure if this it a trend but I will make it a point to check in the morning and before lights out. Does anyone have any ideas what may have caused the increase overnight?....normal?


----------



## bioload (Oct 20, 2009)

Did a few couple test and things don't seem to be going as I thought........or again maybe just to early to make any conclusions.

ORP: 326mV (Back to original range)
pH: 7.18
Drip Rate: 0.73 drops/sec

Nitrate No Change









Test DO as well and there doesn't appear to be a difference???


----------

