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

[McPuff]

Quick question, what do you use to separate the different sized media, or you don’t. Thanks

I would be really careful about using anything smaller than 1" in size or you will likely have issues with clogging.

 

[McPuff]

Quick update on my DND which [i just looked] I set up back in early July of 2025. My nitrates were over 200 at that time. Just did a quick test yesterday and nitrates could be as low as 10 right now! Keep in mind that I am not doing water changes on a regular basis. Usually they are just to remove sediment from the sump but it's pretty infrequent. That is to say that the reactor has been working really well. I may even have to dial back the vinegar a bit so that I can maintain some level of NO3 as I don't want it to go too low (I was thinking that 20 would be ideal). We'll see what the lab analysis says in about a week.

Phosphates have also come down quite a bit though that is due to GFO. It's really hard to color match with the salifert kit (for both NO3 and PO4) but I believe it's somewhere around 0.5 which is also a massive reduction from 1.5 that I measured in December.

Coupled with the change in lights, I have seen a big difference in coral health and once again am seeing actual growth from SPS.

 

[blazn]

Quick update on my DND which [i just looked] I set up back in early July of 2025. My nitrates were over 200 at that time. Just did a quick test yesterday and nitrates could be as low as 10 right now! Keep in mind that I am not doing water changes on a regular basis. Usually they are just to remove sediment from the sump but it's pretty infrequent. That is to say that the reactor has been working really well. I may even have to dial back the vinegar a bit so that I can maintain some level of NO3 as I don't want it to go too low (I was thinking that 20 would be ideal). We'll see what the lab analysis says in about a week.

Phosphates have also come down quite a bit though that is due to GFO. It's really hard to color match with the salifert kit (for both NO3 and PO4) but I believe it's somewhere around 0.5 which is also a massive reduction from 1.5 that I measured in December.

Coupled with the change in lights, I have seen a big difference in coral health and once again am seeing actual growth from SPS.

Thank you for the update, as it just might be what convinces someone to make their own DND. Once you've got one in action and see the results, it is a must have!

 

[ryewalk84]

For those that have done these outside the sump, what am I searching for to ensure the inlet/outlet drains are sealed? What have others used?

 

[McPuff]

For those that have done these outside the sump, what am I searching for to ensure the inlet/outlet drains are sealed? What have others used?

You would need to have a different design to run it outside the sump. Completely gluing parts together would be a necessity... or at least using threaded caps. Would you run it pressurized or still try to make it gravity fed? I think you'll run into some different challenges but you gotta do what you gotta do.

Do you have a working model yet or just some sketches perhaps? We can chime in after seeing what you've got.

 

[ryewalk84]

I’ve collected and assembled my parts and I’m currently in the leak test phase. First tower has an in for tank water, in for carbon and an overflow for blockage. Second tower has the output. Pipes are 4 inch diameter and 32 inch tall.

 

[McPuff]

Looks good! You'll fit quite a lot of media in that thing. Mine holds about 8.5# of the 1" spherical media. Also 4" PVC but it's 24" tall... though I also have a 4" connector at the bottom which is also full of media.

Good luck and keep us posted!

 

[Curiousbranching]

I’ve collected and assembled my parts and I’m currently in the leak test phase. First tower has an in for tank water, in for carbon and an overflow for blockage. Second tower has the output. Pipes are 4 inch diameter and 32 inch tall.

You should change the position of the carbon feed line so that it is considerably higher than the water inlet line to Tower 1. The current position will definitely cause very frequent blockages.

 

[McPuff]

You should change the position of the carbon feed line so that it is considerably higher than the water inlet line to Tower 1. The current position will definitely cause very frequent blockages.

Agree. I put the inlets on the cap for my own as it gave even more height differential with the outlet. Definitely recommend this regardless of whether you're using gravity or pressurizing the reactor.