Poor Man's Nutrients Control - Donovan's Nitrate Destroyer

[olonmv]

Another question. Will the water level on both sides be dependent on the outlets level?

I’m sorry I’m not sure I’m understanding the question correctly.

 

[legionofdoon]

I’m sorry I’m not sure I’m understanding the question correctly.

Will the water level in both towers be set at the height of the drain line?

 

[Steve2020]

Will the water level in both towers be set at the height of the drain line?

The answer is yes, but there is a case where the water in the supply tube will be higher and that is if or when you get a buildup of slime from the carbon dosing. This is why IMO you need to have an emergency drain that is higher than the input line. I had a buildup of slime that raised the water level in the input tube even though I have some large media in it. I ended up having to completely clean my media in both tubes which was a pain because my tubes are just shy of 5ft each which hold a lot of media. I ended up reducing my DIY carbon dosing by 75% and my NO3 has been stable at 8.5ppm for the last month. Since I cleaned the media a month ago the water levels are still equal in both tubes so I am no longer getting that abundance of slime. At least so far.

 

[legionofdoon]

Understanding the science behind it, and following this post for months, honestly I was sceptical, as I have already tried basically everything to bring my nitrates down: refugium, carbon dosing, pellets, resins, media, all brands, all formulas… don’t get me wrong; they do work as they kept my nitrates stable, but nothing, even collectively, was able to bring my nitrates down!!!
I totally get water changes, and yes it is a solution, if you have a smaller tank where these changes actually have a real impact. In larger systems, even large changes have a limited impact, and my levels of nitrate would eventually rise a few days later to previous levels.
I have a 600 litres system with sump, and already I don’t feed like crazy my 15 fishes, with only a frozen mysis cube, pinch of flake and some nori for the tangs, once a day, and they are healthy (not fat) and all active. I still, and have been battling 50ppm nitrate for nearly a year now.
So, to cut it shorter, a gave the DND a shot, and guess what…. IT WORKS!!! I’m so amazed. I will share my build with you soon, with all details, and it took only 15 days to get fully functional. We’ll done Donovan, RIP, and thank you all Reefers for contributing! Keep this post alive!!! Here below, a short video of the nitrogen production from effluent. More to come

Are you going to put your build in this thread or are you going to make a separate one?

 

[legionofdoon]

Ok so I got most of the parts to make one. I was thinking about using aquaforrest's bio fil. Any objections to that and how important is carbon dosing? I'm waiting to buy a doser.

 

[Garf]

Ok so I got most of the parts to make one. I was thinking about using aquaforrest's bio fil. Any objections to that and how important is carbon dosing? I'm waiting to buy a doser.

It appears this thing is a version of a denitrification tower. I tried the tower a long time ago, it did nothin. I was missing the carbon source, obviously. It’s key. This is the reason I doubt the claim it’s much to do with low oxygen, well that and the fast flow through rates that are proposed.

 

[Sean Clark]

It appears this thing is a version of a denitrification tower. I tried the tower a long time ago, it did nothin. I was missing the carbon source, obviously. It’s key. This is the reason I doubt the claim it’s much to do with low oxygen, well that and the fast flow through rates that are proposed.

All the more reason to stick to a simple sulfur denitrator. No carbon source or feeding required and just works.

 

[Garf]

All the more reason to stick to a simple sulfur denitrator. No carbon source or feeding required and just works.

Well that’s a true low oxygen method for sure. Never used one however.

 

[legionofdoon]

It appears this thing is a version of a denitrification tower. I tried the tower a long time ago, it did nothin. I was missing the carbon source, obviously. It’s key. This is the reason I doubt the claim it’s much to do with low oxygen, well that and the fast flow through rates that are proposed.

I thought it was supposed to be a relatively slow flow through rate. 10% water volume per day.

 

[Garf]

I thought it was supposed to be a relatively slow flow through rate. 10% water volume per day.

Carbon is not required in true oxygen depleted denitrification as an energy source, they use nitrogen ((nitrate)). If I’m wrong I’ll hold my hands up but they are firmly in my pockets as it stands.

 

[olonmv]

I thought it was supposed to be a relatively slow flow through rate. 10% water volume per day.

It is. I was doin just that. Today my N03 was at 2.9ppm. I still need to cut back on dose amount. I thought .2ml was all I needed to maintain the 5ppm ish I wanted. I used just one type of media and it worked. I don’t mind carbon dosing especially since it’s such a tiny amount.

 

[legionofdoon]

Carbon is not required in true oxygen depleted denitrification as an energy source, they use nitrogen ((nitrate)). If I’m wrong I’ll hold my hands up but they are firmly in my pockets as it stands.

That makes sense since from what I understand about carbon dosing you feed the bacteria to increase biomass and then it's exported via the skimmer

 

[legionofdoon]

I’m sorry I’m not sure I’m understanding the question correctly.

Where did you get the tank volume x .027 from?

 

[olonmv]

Where did you get the tank volume x .027 from?

I apologize, it’s actually about .024 but to answer your question. I took Donovan’s DND empty volume (4”pvc @ 36” long) of 1.958 and divided it by his tank volume of 80 gallons equals .024. That tells me that .024 of DND volume per gallon of tank volume is what Donavan was doin. This is how I sized my DND and it’s worked as advertised even though I’m using only one type of media. I’ve been maintaining around 5 ppm for the past 2-3 weeks and I’m down to dosing .1ml of vodka a day. Started at 36ppm in the beginning of September.

 

[legionofdoon]

Thanks. Are you running it at 10% tank volume per day or at around and hour transit time?

 

[legionofdoon]

Also how long did it take to get going?

 

[olonmv]

Thanks. Are you running it at 10% tank volume per day or at around and hour transit time?

Flow is set for 10% tank volume per day. My DND turns over about 1.3 gallons daily. That’s equivalent to 10% water change daily once it matures. I still have mine set to about 10% but have drastically reduced my carbon dose (straight cheapo vodka) from 1ml to .1ml.

Also how long did it take to get going?

it started to slowly do its thing like 1 week after the first flow and seeding. I saw my numbers creeping down and had my doubts it was because of the dnd (I thought my numbers were off) but, I currently sit at very low N03 today as opposed to the beginning of September where I was at 36ppm.

 

[legionofdoon]

Any problems with going slightly larger or smaller?

 

[olonmv]

Any problems with going slightly larger or smaller?

If anything, I’d go larger. I imagine going smaller will inhibit its capabilities and it won’t be able to or struggle to keep up with water volume but I could be wrong.

 

[legionofdoon]

Ok now I'm confused. I saw earlier that you should shoot for a dwell time of an hour or sow. If that's the case 1 GPH is equal to 63 ml/min. 10% of my volume per hour would be 17 ml/min so much slower. If the concentration of nitrates is fixed at let's say 100ppm does it really matter what the volume is? 10 gallons at 100ppm is the same concentration as 100 gallons at 100ppm wouldn't it just bring them down faster in the smaller volume?