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

blazn · Oct 31, 2023

I didn't have to deal with a hydrogen sulfide issue, but carbon provides the fuel and a slower flow allows for more time consuming the fuel, so reducing carbon and/or increasing flow should reduce the H2S production. I'd first reduce your carbon dose, then if necessary, increase flow.

piranhaman00 · Dec 5, 2023

What pumps are you tuys using? I can’t get my flow to stabilize. It slowly goes down over time and I start getting H2S formation. I’m currently using ball valves to slow down but debating trying just a low flow pump

Gtinnel · Dec 5, 2023

piranhaman00 said:
What pumps are you tuys using? I can’t get my flow to stabilize. It slowly goes down over time and I start getting H2S formation. I’m currently using ball valves to slow down but debating trying just a low flow pump

I’m using a Neptune pmup directly connected to an outlet with a valve to tune the flow. I would strongly recommend against using it. I also have to fiddle with my valve frequently to keep flow from completely stopping.

blazn · Dec 5, 2023

I just fed mine by splitting off from the feed I already have running to a gfo/activated-carbon dual reactor, which uses a smallish Sicce pump. I'm also only using a ball valve and for the first couple months, I was always having to make the smallest adjustments to it to keep the flow where it needed to be. It finally settled into a good spot, where it's maintaining the flow perfectly with minimal adjustment.

Pntbll687 · Dec 5, 2023

piranhaman00 said:
What pumps are you tuys using? I can’t get my flow to stabilize. It slowly goes down over time and I start getting H2S formation. I’m currently using ball valves to slow down but debating trying just a low flow pump

A versa dosing pump or any adjustable continuous duty pump would work well for this

piranhaman00 · Dec 5, 2023

Ok so others are having to adjust frequently as well. I will keep doing that until I can get it dialed in thanks.

piranhaman00 · Dec 5, 2023

Pntbll687 said:
A versa dosing pump or any adjustable continuous duty pump would work well for this

Wow yes that would be perfect actually, should be a perfect continuous measurable flow. May need to look into that, thanks.

legionofdoon · Dec 25, 2023

piranhaman00 said:
How would I tell?

Sorry so late, you will smell it. The human nose is very sensitive to it. It smells like bad eggs.

legionofdoon · Dec 25, 2023

piranhaman00 said:
I’ve been dealing with hydrogen sulfide with this and have a few questions.

As I’m trying to dial in the effluent , is it better to reduce carbon or increase flow ? Does that H2S production count on carbon at all or is that only from slow flow? I am at about 5 ppm NO3 in effluent. I want 25 so I am curious if it’s better to increase flow or reduce carbon, I want slower flow but I cannot with H2S.

What is the science behind the H2S production?

Once the nitrate is gone the bacteria turn to sulfur. So instead of N2 it produces HS. You can either increase the flow or lower the carbon as someone else said. I increase the flow personally. It helps clear out the mulm that forms inside the chambers. Also I changed mine to small diameter in first chamber then progressively larger to the second chamber. When I had the smaller diameter in the first chamber it clogged really fast.

piranhaman00 · Jan 17, 2024

Anybody using just a single tower design? I believe I made mine too large and cannot get no3 reduction without H2S production. I think there is too much water contact time. Thinking of making the twin just two separate reactors

Joj · Jan 17, 2024

piranhaman00 said:
Anybody using just a single tower design? I believe I made mine too large and cannot get no3 reduction without H2S production. I think there is too much water contact time. Thinking of making the twin just two separate reactors

You probably need more carbon source (ie vodka) added or up your flow. It’s a fine line tuning it initially first 6 months for me

blazn · Jan 18, 2024

The primary issue with using a single tower is ensuring that it creates an anaerobic zone. If I recall, there was some mention of doing so within this thread. If you haven't done so already, I agree with Joj as far as increasing carbon and/or flow. My standard dual tower has been working perfectly and I've never had any noticeable H2S generated. After 49 days, it was fully functional and I'm now down to 6ml of vodka/day to maintain 8-10 NO3.

piranhaman00 · Jan 18, 2024

blazn said:
The primary issue with using a single tower is ensuring that it creates an anaerobic zone. If I recall, there was some mention of doing so within this thread. If you haven't done so already, I agree with Joj as far as increasing carbon and/or flow. My standard dual tower has been working perfectly and I've never had any noticeable H2S generated. After 49 days, it was fully functional and I'm now down to 6ml of vodka/day to maintain 8-10 NO3.

Mine is huge and I think it’s too big. If I increase the flow too much there is no reduction. Increasing the carbon would only generate more H2S.

I believe that the nitrate is all reduced by the time the water gets to the second tower and then H2S is produced.

I have never had nitrate reduction without H2S being produced. Also I don’t even dose carbon anymore and I get H2S and 0 nitrate.

blazn · Jan 18, 2024

piranhaman00 said:
Mine is huge and I think it’s too big. If I increase the flow too much there is no reduction. Increasing the carbon would only generate more H2S.

I believe that the nitrate is all reduced by the time the water gets to the second tower and then H2S is produced.

I have never had nitrate reduction without H2S being produced. Also I don’t even dose carbon anymore and I get H2S and 0 nitrate.

Well, then I'd separate the two towers and test a single tower setup and see what you get. You may want to keep water flowing thru the 2nd tower in some way to keep the bacteria alive, unless you don't anticipate using the 2nd tower again.

piranhaman00 · Jan 18, 2024

blazn said:
Well, then I'd separate the two towers and test a single tower setup and see what you get. You may want to keep water flowing thru the 2nd tower in some way to keep the bacteria alive, unless you don't anticipate using the 2nd tower again.

I plan to use them both

large predator tank

blazn · Jan 18, 2024

piranhaman00 said:
I plan to use them both large predator tank

Glad you have a use for the 2nd tower. Definitely post an update with your outcome, assuming you test out the single tower. Good luck!

Discordian · Feb 14, 2024

I wanted to add my experience to the thread. I read through the whole thing and it was a good read. I have been struggling with high nitrates pretty much since I set up my tank a few years ago. I want to keep SPS, but I have been unable to keep nitrates in a good range.

I was debating between trying a turf scrubber and a donovan's nitrate destroyer. I landed on trying a nitrate destroyer because I have to dose phosphates and a turf scrubber was just going to require more of that. Then a nitrate destroyer just sounded like fun to build and tune.

I have been running mine for 4 days now. It is already reducing nitrates. My tank is at 40 ppm and the effluent is at 20 ppm.

I mostly wanted to share my feedback on building one of these. It was a bit more expensive than I initially thought it would be. The hardware store only had all of the fittings I needed for 4 inch pipe and I needed more matrix than expected. All in it was about $200. That includes a small pump, bottled bacteria, pipes, fittings, cement and matrix.

It does seem like some folks have struggled with tuning and clogging. So I hope I don't struggle too much with that. I do plan on posting further updates - wanted to give back and share my experience with anyone that comes after me. Tips and suggestions are welcome!

blazn · Feb 14, 2024

Discordian said:
I wanted to add my experience to the thread. I read through the whole thing and it was a good read. I have been struggling with high nitrates pretty much since I set up my tank a few years ago. I want to keep SPS, but I have been unable to keep nitrates in a good range.

I was debating between trying a turf scrubber and a donovan's nitrate destroyer. I landed on trying a nitrate destroyer because I have to dose phosphates and a turf scrubber was just going to require more of that. Then a nitrate destroyer just sounded like fun to build and tune.

I have been running mine for 4 days now. It is already reducing nitrates. My tank is at 40 ppm and the effluent is at 20 ppm.

I mostly wanted to share my feedback on building one of these. It was a bit more expensive than I initially thought it would be. The hardware store only had all of the fittings I needed for 4 inch pipe and I needed more matrix than expected. All in it was about $200. That includes a small pump, bottled bacteria, pipes, fittings, cement and matrix.

It does seem like some folks have struggled with tuning and clogging. So I hope I don't struggle too much with that. I do plan on posting further updates - wanted to give back and share my experience with anyone that comes after me. Tips and suggestions are welcome!

Welcome to the Donovan's Nitrate Destroyer club! Thanks for sharing your experience!

piranhaman00 · Feb 14, 2024

I used half inch connectors and have had no issues with clogging. I find it hard to tune , I believe I made mine too big (10ft of 4” pvc) so I get a lot of H2S production. To fix this I run the effluent through a reactor containing carbon and GFO. This catalyzes a reaction to remove the H2S. Not ideal but works well.

Tritie · Apr 13, 2024

I am trying to set one up for myself. I'm really space limited. I considered doing an external one to make it bigger, but I have a fear of tubing coming off leading to a flood. At least if the tubing pops off, water will just stay in the sump. I have a system that is probably around 65 gallons. I had to use 3 inch pipes because that's what I can fit in my sump. Someone on here did a denitrator for a 65 gallon tank using 58 inches of pipe (total...I assume and hope), but I could not get that length into my sump, so I'm stuck with 53.5 inches total. I have an abundance of media in my sump that is already colonized (Seachem pumice, which I probably won't use much off, Siporax and MarinePure).

I'm hoping this ends up being temporary. I have some angel hair chaeto in QT. I've killed a lot of chaeto in the last 2 years and I struggle to get it to grow. I hear angelhair is better, but my system also eats up phos.