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

McPuff · Jun 23, 2026

timry2 said:
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 · Wednesday at 3:45 PM

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 · Wednesday at 3:57 PM

McPuff said:
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!