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

[Discordian]

I have been meaning to come back and post a 1 year update, but it has been a year and a half.

I LOVE my donovan's nitrate destroyer. I struggle for my first three years in this hobby with nitrates. Not anymore! It is so easy to control nitrates and set them basically at whatever number I want. Just change the dosing schedule and they go up or down. It took me a bit to find the right flow, but now I barely touch it. I went from struggling to keep nitrates under control to today I tested at 3.2. My corals are all doing great and algea isn't really an issue.

I used larger media and I have had zero issues with clogging or flow.

If I have one complaint it is that if I am not careful I can bottom out phosphates, which feels like a better problem to have then not being able to control them. It is pretty easy to dose neophos when needed.

If you are struggling with nitrates this is a fantastic option.

 

[blazn]

I have been meaning to come back and post a 1 year update, but it has been a year and a half.

I LOVE my donovan's nitrate destroyer. I struggle for my first three years in this hobby with nitrates. Not anymore! It is so easy to control nitrates and set them basically at whatever number I want. Just change the dosing schedule and they go up or down. It took me a bit to find the right flow, but now I barely touch it. I went from struggling to keep nitrates under control to today I tested at 3.2. My corals are all doing great and algea isn't really an issue.

I used larger media and I have had zero issues with clogging or flow.

If I have one complaint it is that if I am not careful I can bottom out phosphates, which feels like a better problem to have then not being able to control them. It is pretty easy to dose neophos when needed.

If you are struggling with nitrates this is a fantastic option.

Thank you for the update Discordian! Always great to 'hear' from others how much a DND has improved their reefing experience! I know I'll never not have a DND in my reef system, as it is an essential tool for me.

 

[Discordian]

I have been meaning to come back and post a 1 year update, but it has been a year and a half.

I LOVE my donovan's nitrate destroyer. I struggle for my first three years in this hobby with nitrates. Not anymore! It is so easy to control nitrates and set them basically at whatever number I want. Just change the dosing schedule and they go up or down. It took me a bit to find the right flow, but now I barely touch it. I went from struggling to keep nitrates under control to today I tested at 3.2. My corals are all doing great and algea isn't really an issue.

I used larger media and I have had zero issues with clogging or flow.

If I have one complaint it is that if I am not careful I can bottom out phosphates, which feels like a better problem to have then not being able to control them. It is pretty easy to dose neophos when needed.

If you are struggling with nitrates this is a fantastic option.

Thank you for the update Discordian! Always great to 'hear' from others how much a DND has improved their reefing experience! I know I'll never not have a DND in my reef system, as it is an essential tool for me.

I have really come to the same conclusion. I would rather have it than a skimmer. Although I do run both. And I find it way better than a refugium. I have never run a turf scrubber, mostly due to cost, so I can't compare to that. But for me it just works and allows a level of control that is difficult to match with anything else.

 

[McPuff]

Hey, update time! Over the weekend I realized the flow was about 2x too high. Lowered it and yesterday I thought I imagined a bit of snotty stuff coming out of the effluent. This morning I didn't have to imagine... it's happening! Currently dosing 10ml/day of vinegar and spacing it out across 5 intervals. I'll start testing effluent today [then gone until Sunday] and continue from there to determine dosing and flow. I have a LOT of nitrate to reduce so really looking forward to seeing the results. Really love the simplicity of the reactor and can't wait to remove the algae scrubber. 1 less pump and 2 fewer lights. And several fewer hoses/pipes!

Will try to provide regular updates on the progress.

 

[blazn]

Hey, update time! Over the weekend I realized the flow was about 2x too high. Lowered it and yesterday I thought I imagined a bit of snotty stuff coming out of the effluent. This morning I didn't have to imagine... it's happening! Currently dosing 10ml/day of vinegar and spacing it out across 5 intervals. I'll start testing effluent today [then gone until Sunday] and continue from there to determine dosing and flow. I have a LOT of nitrate to reduce so really looking forward to seeing the results. Really love the simplicity of the reactor and can't wait to remove the algae scrubber. 1 less pump and 2 fewer lights. And several fewer hoses/pipes!

Will try to provide regular updates on the progress.

Awesome! Looks like you're well on your way to getting those nitrates down to manageable levels. Thanks for the update!

 

[Curiousbranching]

While trying to find the most optimal way to run my DND, I came across the user manual for Deltec NFP — a device that works pretty similarly to DND. I found it super helpful, especially for beginners like me! It explains things

My DND has been running smoothly for a few months now, and I think it’s awesome and easy to use. I can totally control any NO3 level I want just by adjusting the flow or adding more carbon — it’s that simple

 

[blazn]

While trying to find the most optimal way to run my DND, I came across the user manual for Deltec NFP — a device that works pretty similarly to DND. I found it super helpful, especially for beginners like me! It explains things

My DND has been running smoothly for a few months now, and I think it’s awesome and easy to use. I can totally control any NO3 level I want just by adjusting the flow or adding more carbon — it’s that simple

Thanks for adding the Deltec reactor instructions to the thread! Especially interesting to me was "Shut off the water supply to the reactor using tap ‘Y’ and leave it like this for 3 days to allow the oxygen in the water to be used up and to allow growth of the anaerobic bacteria." I don't recall anything like that contained in this thread, but I wonder if that would speed up the initial 'break in' period.

 

[Stang67]

I am going to attempt to build one of these next weekend. In the meantime I'll read through the posts. Is there any tips or tricks I need to make sure I am doing at start up?

 

[Curiousbranching]

Thanks for adding the Deltec reactor instructions to the thread! Especially interesting to me was "Shut off the water supply to the reactor using tap ‘Y’ and leave it like this for 3 days to allow the oxygen in the water to be used up and to allow growth of the anaerobic bacteria." I don't recall anything like that contained in this thread, but I wonder if that would speed up the initial 'break in' period.

I figure that’ll do the trick, right? Isn’t it true that everyone’s still telling beginners to start with the lowest flow possible? I think that’s actually a pretty smart move. Instead of letting bacteria grow so much they eat up all the oxygen, we can be proactive and make that happen faster.

Oh, quick question: does the white mucus coming out smell? I don’t notice any odor in the room, but when I get my nose right up close to the outlet, I catch a faint sulfur smell. The ORP in the tank is also oddly low—like 40-50. Could be because of the salt I used, or maybe I accidentally used sulfur materials. The corals in the tank are growing beautifully, so I’m just curious since most people’s ORP levels are above 300.

 

[Curiousbranching]

I am going to attempt to build one of these next weekend. In the meantime I'll read through the posts. Is there any tips or tricks I need to make sure I am doing at start up?

Oh, I’m still pretty new myself—my DND has only been running for about three months. But I’ve picked up a few tips that might help you out!"

1. Make a detailed checklist of everything you need beforehand. There are a lot of small things, and you’ll hate having to stop and wait (or make extra trips) if you’re not prepared.
2. Use larger-sized materials—avoid anything smaller than ½" because it’ll clog up fast once you start dosing carbohydrates.
3. Your IN/OUT lines should be around ½"–¾" in size. I initially used 2/5", and by Week 3, the OUT line was completely blocked by bacterial buildup. This caused water to backflow into the carbohydrate dosing line. You might want to drill an emergency overflow hole in Tower 1 just in case the same thing happens to you.
4. Whenever you’re unsure, just ask here! There are plenty of really helpful, friendly people who’ll be happy to guide you.

 

[Stang67]

Oh, I’m still pretty new myself—my DND has only been running for about three months. But I’ve picked up a few tips that might help you out!"

1. Make a detailed checklist of everything you need beforehand. There are a lot of small things, and you’ll hate having to stop and wait (or make extra trips) if you’re not prepared.
2. Use larger-sized materials—avoid anything smaller than ½" because it’ll clog up fast once you start dosing carbohydrates.
3. Your IN/OUT lines should be around ½"–¾" in size. I initially used 2/5", and by Week 3, the OUT line was completely blocked by bacterial buildup. This caused water to backflow into the carbohydrate dosing line. You might want to drill an emergency overflow hole in Tower 1 just in case the same thing happens to you.
4. Whenever you’re unsure, just ask here! There are plenty of really helpful, friendly people who’ll be happy to guide you.

Awesome thanks!

 

[blazn]

Oh, quick question: does the white mucus coming out smell? I don’t notice any odor in the room, but when I get my nose right up close to the outlet, I catch a faint sulfur smell. The ORP in the tank is also oddly low—like 40-50. Could be because of the salt I used, or maybe I accidentally used sulfur materials. The corals in the tank are growing beautifully, so I’m just curious since most people’s ORP levels are above 300.

The DND output certainly could have a sulfur smell. Like you mentioned in your other post, I do have "an emergency overflow hole in Tower 1" and when there's too much flow, causing a back-flow thru that overflow hole, I'll definitely smell sulfur. My sump, with the DND, is behind the wall of my DT and typically if there's any back-flow going on, I'll notice the sulfur smell when I walk into that room and I instantly know I need to reduce flow.

 

[McPuff]

It's been almost 3 weeks since my last post. The reactor is definitely working! The effluent is down to about 50 and that is with dosing 20ml/day vinegar. I'll keep increasing ~1ml/day until I get to 30 ml if necessary. I will echo what @Curiousbranching said above... the effluent line will clog at times if you use a 1/4" tube. I have heard the same from a local reefer friend too. He just puts up with it and said that 3/8" effluent line made it tough to keep air from getting into the anoxic chamber. For now, that's what I'm doing as well... unless it starts to clog too often.

 

[JonoH]

It's been almost 3 weeks since my last post. The reactor is definitely working! The effluent is down to about 50 and that is with dosing 20ml/day vinegar. I'll keep increasing ~1ml/day until I get to 30 ml if necessary. I will echo what @Curiousbranching said above... the effluent line will clog at times if you use a 1/4" tube. I have heard the same from a local reefer friend too. He just puts up with it and said that 3/8" effluent line made it tough to keep air from getting into the anoxic chamber. For now, that's what I'm doing as well... unless it starts to clog too often.

What size tank are you running this on?

 

[McPuff]

What size tank are you running this on?

It is a 300

 

[JGT]

Hi all! Adding my own experience to the thread... I just set up my own DND a couple of weeks ago and got it online about 9 days ago. It's a pretty big reactor as I used 4" pvc (~24" high and 20" wide). There are about 8.5kg of media inside. My system is approx 300 gal of actual water (300DD, 75g attached "lagoon", 80g sump). Nitrates were ~200 (yes, that high!) when I last sent in to ATI. I dosed prodibio for 5 days and decided to dose vinegar as the carbon source since I already have it on hand. Just doing the 5ml / day and have been dosing for 4 days so far. I haven't yet seen any bacterial slime appear at the effluent line. My flow is about as low as it can go without dripping but given the size of my reactor it may still be too early to see strong results. After looking at the posts higher on this page, it got me thinking that maybe I should check the input pipe to see how the bioballs look. If not today, I'll at least check it sometime this weekend. Then I can assess if I actually need to increase the flow which could very well be the case. I haven't yet measured the effluent but will do that today. Here is a pic of the reactor when I first set it up. Pretty simple!

Just curious, you say 8.5kg of media which would be around 18.8 pounds which figure can’t be right nor does the pic of your reactor look anywhere capable of holding that amount of media. I’ve got 250 gallons so using your example to derive what I’ll need. Thanks.

 

[McPuff]

Just curious, you say 8.5kg of media which would be around 18.8 pounds which figure can’t be right nor does the pic of your reactor look anywhere capable of holding that amount of media. I’ve got 250 gallons so using your example to derive what I’ll need. Thanks.

Yes, that is correct. The reactor is made of 4" PVC, stands almost 2' tall and is about 20" between towers. It's big and holds a lot of media. I ordered 5 boxes of 2kg media and used a little more than 4 boxes. The media is fairly dense so it doesn't take much volume to weight a lot. I thought the reactor would be overkill for my system but I still haven't achieved 0ppm on the effluent. Last I checked a couple days ago and it was still somewhere around 50ppm. That reminds me... I need to increase vinegar dosing again.

 

[JGT]

Yes, that is correct. The reactor is made of 4" PVC, stands almost 2' tall and is about 20" between towers. It's big and holds a lot of media. I ordered 5 boxes of 2kg media and used a little more than 4 boxes. The media is fairly dense so it doesn't take much volume to weight a lot. I thought the reactor would be overkill for my system but I still haven't achieved 0ppm on the effluent. Last I checked a couple days ago and it was still somewhere around 50ppm. That reminds me... I need to increase vinegar dosing again.

OK, thanks for the confirmation.

 

[JGT]

Also, I assume the bottom of your tees that sit on the sump floor are sealed? Your caps are glued on removeable ?

 

[McPuff]

Also, I assume the bottom of your tees that sit on the sump floor are sealed? Your caps are glued on removeable ?

That's correct. I have knock-out caps in there... but I did end up sealing them with silicone because they were sieves. So now they should be very secure with ZERO air/water getting in or out.