DIY Natureef Style Denitrator Build and Data thread...

[bmanzie]

Originally Posted by mrx66699

Thanks bill it came out better than I thought it would ....just don't like where I was going to install it ....think I will build a stand tomorrow at the end of the sump

I think you should tear down that wall and go back a little further. Lol

[mpfeiffer1]

Looking great...Excited about seeing the data as it unfolds. Stupid question but I will ask, "Why eggcrate?" I understand that you need to have some surface media to grow the bacteria but wouldn't the 90 angles make it difficult to flush without some type of buildup in the poor flow areas. Just curious...

[mrx66699]

The flow will come from the sides circulation small pump...when it flushes you dont want it flushing washing all the bacteria out ....it will build up into a slime like substance...all over the egg crates

[mrx66699]

Built the stand to sit at the end of my system instead of on the side ....now it sits next to my frag tank with just as easy access .....almost there after thus location changes setback..







Drain hard plumbed .....



And it will drain into the back of my skimmer chamber ....

[Josh40996]

Originally Posted by mrx66699

Built the stand to sit at the end of my system instead of on the side ....now it sits next to my frag tank with just as easy access .....almost there after thus location changes setback..







Drain hard plumbed .....



And it will drain into the back of my skimmer chamber ....

looking good, is it operational now?

[StevieK]

interesting build. i am hoping to tag along and learn. wondering what size chamber you would recommend for a 200g system. Also, as i cannot make out the pics, do you have a diagram of the guts of the system?

[mrx66699]

Originally Posted by Josh40996

looking good, is it operational now?

yes it is now operational will be seeding it with bacteria from another today.....

Originally Posted by StevieK

interesting build. i am hoping to tag along and learn. wondering what size chamber you would recommend for a 200g system. Also, as i cannot make out the pics, do you have a diagram of the guts of the system?

yes I have a diagram....some of the pics are through photobucket and others are through tapatalk so not sure why you can see them ....and for a 200 gal system you would only need 5-15 gal at the most

[StevieK]

Sorry MrX,

Let me restate. I can see the pics, but cannot quite make out the chambers. Maybe I need a bigger screen. Oh and younger eyes.

[mrx66699]

lol ahh ok I will take some more pictures tonight of the inside chamber....it is one large chamber that has the eggcrate in the middle as a place for the bacteria to grow on....each set of eggcrate has a spacer in between the next set ...as bacteria start to grow it will start to clog up the eggcrate and you do not want the slow flow inside the chamber to have dead spots where the water is not circulating ....I just made the spacers out of 1.5 pvc cut to 1.5 in each and placed them between to act as a spacer then everything is zip tied together .....also the eggcrate has to be positioned so that it can not float up as nitrogen gas is produced in the reaction taking place in the chamber so some of these are cut just to fit all the way to the top and hold the entire amount of the eggcrate in place...

[Josh40996]

Sorry for being a pest but I have a question.

Are you using power heads inside the chamber to keep the water circulating? My understanding is that the bacteria responsible for converting Nitrate into Nitrogen gas are anaerobic? If so, how do you lower the O2 levels fast enough for there to be enough time for the bacteria to do their thing before the next batch of oxygen/nitrate loaded water comes in?

Does the presence of O2 in the fresh (salt) water not kill of the bacteria?

I understand that this is a proven method of Nitrate Removal so I must be going wrong somewhere

Thanks.

[mrx66699]

Originally Posted by Josh40996

Sorry for being a pest but I have a question.

Are you using power heads inside the chamber to keep the water circulating? My understanding is that the bacteria responsible for converting Nitrate into Nitrogen gas are anaerobic? If so, how do you lower the O2 levels fast enough for there to be enough time for the bacteria to do their thing before the next batch of oxygen/nitrate loaded water comes in?

Does the presence of O2 in the fresh (salt) water not kill of the bacteria?

I understand that this is a proven method of Nitrate Removal so I must be going wrong somewhere

Thanks.

Please ask away .....You are on the right track ....water circulation is needed but not surface tension introducing more o2 ...power heads are ok but more of a flow is needed than a push....koralia style pumps seem to work best although a maxijet in the first few months will work fine but eventually will clog up .....the bacteria will feed on the o2 rather than the nitrate as explained to me which is an easier process for them so if its present they will not work as efficiently for you and its this feeding on the nitrate that is what we are seeking so introduction of o2 is not a wanted result...o2's presence in the water is not killing the bacteria only slowing it but exposure to o2 will kill the bacteria as explained to me....Dr Thompson could prolly do a better job of explaining this than I can, he was over last night and said he would be putting up some information today that will help with some of the chemistry questions....

on another note we are operational as of last night and the seed bacteria was introduced, flush time measured which this 30 gal chamber being feed with a mag 7 through some short 1/2 in plumbing runs took 5:20, 1 in drain located just at the top of the chamber gravity release back into the sump worked flawlessly and best of all no leeks unless if we count when doc lifted the maxijet out of the water to adjust it and it sprayed him lol

[mrx66699]

Another note on the build

1st .....I haddent noticed until upon further review last night the feed pipe would be nice if it feed the incoming water on the bottom of the chamber but this will cause a back syphon when the timed pump shuts off so the pipe will need to be positioned with a release just above the desired water level in the chamber (I had to adjust this) so it has no back syphon

2nd.....the drain coming back into the sump should be positioned right about the water level near your skimmer return as the water returning back to the system will be depleted of 02 as was discussed in the above post....but dont have the return pipe in the water as no added back pressure is desired and o2 is desired upon return to the system

[SPotter]

great update!!!! i was wondering about the positioning and depth of the feed line and back flow issues. Couple of questions for you....
do you continually run the maxijet or is that on a timer?
is the mag 7 run wide open and is that 5 hours 20 mins or 5 mins 20 sec?

[mrx66699]

Maxijet or similar in chamber flow pump runs 24/7 for continual circulation....mag 7 filling running wide open and it took 5 min 20 sec to fill ....I am going to set my controller to power on this pump for close to 4 times this amount for the flush that will ensure almost a 100% flush of the chamber before the next cycle would start

[Josh40996]

Originally Posted by mrx66699

Please ask away .....You are on the right track ....water circulation is needed but not surface tension introducing more o2 ...power heads are ok but more of a flow is needed than a push....koralia style pumps seem to work best although a maxijet in the first few months will work fine but eventually will clog up .....the bacteria will feed on the o2 rather than the nitrate as explained to me which is an easier process for them so if its present they will not work as efficiently for you and its this feeding on the nitrate that is what we are seeking so introduction of o2 is not a wanted result...o2's presence in the water is not killing the bacteria only slowing it but exposure to o2 will kill the bacteria as explained to me....Dr Thompson could prolly do a better job of explaining this than I can, he was over last night and said he would be putting up some information today that will help with some of the chemistry questions....



on another note we are operational as of last night and the seed bacteria was introduced, flush time measured which this 30 gal chamber being feed with a mag 7 through some short 1/2 in plumbing runs took 5:20, 1 in drain located just at the top of the chamber gravity release back into the sump worked flawlessly and best of all no leeks unless if we count when doc lifted the maxijet out of the water to adjust it and it sprayed him lol

Ahh, I am on the same wavelength now. Thank you.

That was my next question about not cycling the same batch of water. :P Keep up the good work.

[mrx66699]

yes this 5 min 20 sec was just a fill time as a baseline for flushing not a cycle time

[DRThompson]

Originally Posted by Josh40996

My understanding is that the bacteria responsible for converting Nitrate into Nitrogen gas are anaerobic? If so, how do you lower the O2 levels fast enough for there to be enough time for the bacteria to do their thing before the next batch of oxygen/nitrate loaded water comes in?

Does the presence of O2 in the fresh (salt) water not kill of the bacteria?

I understand that this is a proven method of Nitrate Removal so I must be going wrong somewhere

Thanks.

Matt asked me to comment on this:

the SHORT Theory behind denitrification using a methanol chamber:

The denitrification is carried out under anoxic (low oxygen) conditions by a broad range of heterotrophic bacteria (mainly pseudomonas sp) through the process of nitrate dissimilation, in which nitrite and/or nitrate are used as the electron acceptor rather than oxygen. The bacteria can use either oxygen or oxidized nitrogen while oxidizing organic material. Thus, for the biological denitrification to be effective it needs to be carried out in the absence of oxygen. This is often the rate limiting step in the process for cycle completion.

[DRThompson]

I thought I should include some information about dosing.

Here is the equation for the anoxic reaction in the chamber to convert nitrate to Nitrogen gas using Methanol utilizing heterotrophic bacteria.....(roughly)

5 CH3OH + 6 NO3- ----> 3 N2(gas) + 5 CO2 + 7 H2O + 6 OH-

Our dosing method:
After a lot of research and experience with my own methanol denitrator we will be using a 3:1 Methanol to Nitrate dosing ratio. Again, we are going with a more conservative approach. Matt and I will dose adjust as we follow the first few cycles to completion.

Matt's water tested roughly 25mg/L of Nitrates, its probably higher but I thought we should be conservative. The volume of the chamber is roughly 30gal or approx 120L which gives us (25mg/L*120L=3000mg or 3grams of nitrogen)

At a 3:1 ratio it will take approx 9gm of Methanol to remove 3gm of Nitrate. Since the specific gravity of Methanol is approx 0.8 that would give us a starting dose of 11.25ml. To keep things easy we are rounding to 10ml of pure methanol for the initial dosing .

Also, because of the volatility of methanol we will be using a 50% v/v solution of methanol and water. This changes the initial dose to 20ml.

After filling the chamber with tank water and seeding with a small amount of bacteria from my biodenitrater we started the first cycle at 9pm Feb 24th with 20ml of our 50% methanol solution.

[DRThompson]

I'll be using the term PEAK reaction: For us the peak of the reaction happens when the system goes anoxic and the bacteria start removing the nitrogen(nitrates). IME, this usually happens about 3/4 of the way thru the cycle and can be instrumental in finding the end of a cycle.

Parameters we will be monitoring:

Expected Visual Observations:

The growth of the bacteria is VERY noticeable. It is thick and slimy. It is clear to slightly brown in color.

Also, as the reaction nears completion nitrogen gas bubbles will often form on the eggcrate.

Expected Test kit observations:

Nitrate: Salifert and API - Matt's Tank water tested at 25-50mg/L on salifert. (higher readings are harder to read) Obviously, it is expected to be near 0 at cycle completion.

Nitrite: API - At the peak of the cycle there should be a noticeable increase in nitrite. Our initial test at the start of the cycle was 0 on the API test kit.

ORP: We should see a drop in ORP (approx -100 to -200 at the peak of the reaction). Matt is still working on getting the ORP meter up and running.

Dissolved Oxygen: We will be using a RED SEA dissolved oxygen test kit. Normal Seawater will read between 6-7ppm. There should be a marked drop in dissolved Oxygen indicating the peak of the reaction. Also, at the end of the cycle it is expected to be around 1-2ppm.

We are somewhat limited by the accuracy of our home test kits but I am confident we should still be able to successfully locate the peak and end of the cycle.

At the cycle endpoint the water in the chamber should be:

Free of nitrates
Low in oxygen
Lower in pH than start
higher in Alk than start
Loaded full of beneficial bacteria

When we've determined the endpoint of each cycle, the water will be flushed thru the chamber using an external pump (mag 7) and then the cycle starts over. Our observations showed it took the Mag7 approx 5 min to fill the chamber when empty. To ensure a proper flush we will run the mag7 for about 20min at the end of each cycle. Once there is a predictable cycle under 24 hours we will automate it with his apex. Our goal is to have this 30gal chamber cycle 3-4 times per day. At 3-4 cycles per day it would be like a 10-15% water change daily (comparatively speaking for removing nitrates)

An important note: we have positioned the output of the chamber so it dumps the water that is exiting the chamber on top of the skimmer intake. This will allow the skimmer to chew up most of the excess bacteria. While beneficial to the system it is WAY more than most systems can handle and would become food for nuisance algae if not properly skimmed out.

[mrx66699]

Very nice Doc I don't think I could have said it better myself lol

[SPotter]

Great write up Dave! So let me see if I understand the timing of the cycle properly. If I am reading it correctly you are saying that initially it will take as long as 24 hours for a cycle to be completed but as the denitrator matures a cycle should be complete in 6-8 hrs?

[DRThompson]

Originally Posted by SPotter

Great write up Dave! So let me see if I understand the timing of the cycle properly. If I am reading it correctly you are saying that initially it will take as long as 24 hours for a cycle to be completed but as the denitrator matures a cycle should be complete in 6-8 hrs?

When I started my denitrator my first cycle took about 2 weeks. It really depends on your starting parameters and how fast you can get the bacteria to grow. It is highly unlikely anyone's first cycle will complete in 24 hours. As the bacteria populate the chamber the cycle time will shorten. I told Matt it may take a month or so to get a cycle time under 24 hours. As with most things in this hobby, patience and time are very important for success. We are posting our experiement on this forum to benefit anyone who may be interested in starting a biodenitrator.

We added fresh bacteria from my denitrator chamber to help seed it. At about the 20 hour mark, Matt's observed an explosion of bacteria growth in the chamber. He tells me the water is cloudy and full of thick slimy bacteria. This is GREAT; we are growing heterotrophic bacteria! Matt also tested nitrites and nitrates at around the 24 hour mark and they were both elevated. However, I don't think it has gone anoxic yet. I suspect his biopellet reactor is responsible for the bacterial bloom in the chamber. I'm not totally convinced we are getting the right bacteria to grow in the chamber. If we looked at the bacteria under a microscope I could maybe determine if it is gram negative (Pseudomonas sp) but have no way of identifying if it will eat up the nitrates once the oxygen is gone. Again, we lack specialized scientific equipment so for now we will just let it "cook" a bit longer to get in the anoxic stage.


He's is going to run oxygen, nitrite, and nitrate tests later today at about 4pm (43 hours into the first cycle). We'll post the results but I don't believe we are at the PEAK of the cycle yet.

[SPotter]

This is all great info Matt and Dave! The scary part is Im actually starting to understand it... My new tank wont be ready to go for a couple of months so this gives me plenty of time to follow along with you to watch the results.

[mrx66699]

Originally Posted by SPotter

This is all great info Matt and Dave! The scary part is Im actually starting to understand it... .

For myself it always seemed a simple thing to understand on the surface level but I had no clue it was this deep and what was actually happening with the chemistry level and it wasnt until I started speaking with Dave that I have actually started to fully understand on a sub level what is actually taking place.....I had one on my first DT here in Florida and all I knew was it just worked better than any of the other setups that I had tried up until that point.....

[SPotter]

I am curious about why this system seems to be more popular in Fl than other parts of the country?