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

[McPuff]

Anyone built a new DND recently?

Mine has been chugging along nicely. Nitrates were in the 30's the last test about a month ago. I'm actually pretty content with that level... perhaps 20 - 30. Phosphates have been reduced substantially as well. Down to 0.7 as of a month ago and likely lower still (need to test again). Corals are looking much better and I'm seeing new growth on just about everything. I continue to work on the sand bed and ensure pumps are working efficiently. Very happy with the reactor though.

 

[salty joe]

good to hear, any chance you could post a couple pics?

 

[McPuff]

Pictures of the tank itself or the ugly homemade sump and reactor.

 

[McPuff]

I'll take a couple pics this week and post.

 

[salty joe]

In my book, anything home made for a reef tank that works well is a thing of beauty!

 

[Curiousbranching]

Well, would you look at that—it’s officially been one year since my denitrator kicked into action. Today I finally open reactor #1 to give it a good cleaning, since it’s been clogging up lately. Turns out a whole mass of beneficial bacteria had grown into a thick, web-like mat right on the surface, even plugging up the water inlet pipe. But after just a few simple cleaning steps following a full year of nonstop operation, my denitrator is back to running like a champ. And get this—my nitrate levels are practically undetectable now, even though I still feed my fish like they’re living at an all-you-can-eat buffet.

 

[PPBlimpy]

Glad this post came back up. I saw it about a year ago and thought about building one and never got around to it. I am starting to carbon dose and think it is time to build one.

I have 6 lbs of these Aquaneat bio rings from amazon that are unused, anyone use these? Have read about ceramic media leaching aluminum.

If I can use these I would do a mix of large rock rubble and these rings. I believe I have all the plumbing supplies to build the rest of the reactor sitting in the basement.

The other option I have is a 24" tall second chamber from an old Calxr. I was using it as a cryptic fuge, had it full of rock rubble, I already had this basically installed but running 300gph, I should have slowed the feed and started dosing directly. Just removed it a month ago.

 

[McPuff]

Well, would you look at that—it’s officially been one year since my denitrator kicked into action. Today I finally open reactor #1 to give it a good cleaning, since it’s been clogging up lately. Turns out a whole mass of beneficial bacteria had grown into a thick, web-like mat right on the surface, even plugging up the water inlet pipe. But after just a few simple cleaning steps following a full year of nonstop operation, my denitrator is back to running like a champ. And get this—my nitrate levels are practically undetectable now, even though I still feed my fish like they’re living at an all-you-can-eat buffet.

How did you clean it out? Just pick out the mass? Looks like stroganof.

 

[McPuff]

Glad this post came back up. I saw it about a year ago and thought about building one and never got around to it. I am starting to carbon dose and think it is time to build one.

I have 6 lbs of these Aquaneat bio rings from amazon that are unused, anyone use these? Have read about ceramic media leaching aluminum.

If I can use these I would do a mix of large rock rubble and these rings. I believe I have all the plumbing supplies to build the rest of the reactor sitting in the basement.

The other option I have is a 24" tall second chamber from an old Calxr. I was using it as a cryptic fuge, had it full of rock rubble, I already had this basically installed but running 300gph, I should have slowed the feed and started dosing directly. Just removed it a month ago.

How large are those aquaneat rings? I believe they are kind of small as I remember seeing them when I searched for my own media. You want to have large media so it can't get clogged too easily by settling together too closely. Most people use the 1" ceramic spheres which have been great for me. That is all I used. You can add some rock but if may break down and then start to form low/no flow areas.

 

[PPBlimpy]

They might be 3/4 inch dimeter with a 1/4 inch thru hole. they are media you would find in canister filters. came with a tank I had bought.
I was originally thinking about handing them out to a couple local friends with tanks and have them throw them in their sumps for a month and then i would collect them and put them in my new tank.

but reading ceramic like this may leach aluminum and don't want to give that to friends tanks

 

[McPuff]

I think that the poor quality ceramic media are the ones responsible for that reputation of leaching aluminum. I got the maxxspect nano-tech bio spheres and they seem to be really good. They are actually quite hard, unless the blocks I used to have. I've had them in my tank for about a year and the aluminum has not gone up at all.

 

[PPBlimpy]

I think that the poor quality ceramic media are the ones responsible for that reputation of leaching aluminum. I got the maxxspect nano-tech bio spheres and they seem to be really good. They are actually quite hard, unless the blocks I used to have. I've had them in my tank for about a year and the aluminum has not gone up at all.

I will look into those.

 

[salty joe]

I think that the poor quality ceramic media are the ones responsible for that reputation of leaching aluminum. I got the maxxspect nano-tech bio spheres and they seem to be really good. They are actually quite hard, unless the blocks I used to have. I've had them in my tank for about a year and the aluminum has not gone up at all.

do you use ICP?

 

[McPuff]

do you use ICP?

Yes, probably 4 times per year as I use reefmoonshiners method.

 

[Curiousbranching]

How did you clean it out? Just pick out the mass? Looks like stroganof.

So I just went ahead and cleaned a few of those top-layer filter balls. The ones underneath? Barely need any love — I can see just a wispy little cloud of biomass clinging to them, like they're wearing the faintest smoke jacket. Same deal with Tower #2 — practically spotless.

Oh, and I keep seeing little gas bubbles fizzing out of Tower #2 nonstop. Someone in this thread mentioned those are nitrogen bubbles, and yeah, that totally checks out — because that lovely rotten-egg stink from the first few months? Gone. Buh-bye

 

[Reef Man]

Hi, It looks like I will build one as my nitrates are over 85. How do you clean this ? when you open an clean I think you will lost the biological bacteria and need to start again? what happen during that time with the No3? it will go up, isnt? how do you maintain it meanwhile?

 

[timry2]

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

 

[blazn]

Hi, It looks like I will build one as my nitrates are over 85. How do you clean this ? when you open an clean I think you will lost the biological bacteria and need to start again? what happen during that time with the No3? it will go up, isnt? how do you maintain it meanwhile?

I've had my DND in production for just about 3 years now and I've only had to 'clean' it once, about 18 months after it was put into production. I separated the two PVC tubes and flushed no more than a gallon of RODI water down each of the tubes. I noticed that the 2nd tube, from which the output flows, had much less visible bacteria growth than the first. So, assuming I'll need to 'clean' it again in the near future, I expect I'll only flush the 1st tube this time, especially considering that most of the nitrate reducing bacteria (anaerobic) would be in the 2nd tube anyway.

I was surprised in that my NO3 level really was minimally affected by the 'cleaning' process. So, I would not be concerned about performing 'cleaning' on a DND, just be prepared to do so when needed.

After 3 years of use, my appreciation for my DND has not diminished at all. I recommend it for anyone dealing with high NO3!!

 

[blazn]

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

I'd recommend mixing the different sized media together. You don't gain anything by separating them by sizes, but by mixing them together, you can create more areas for the water to flow. The main point with the media is to have it be porous material and not packed together such that it can end up blocking water flow.

 

[timry2]

I'd recommend mixing the different sized media together. You don't gain anything by separating them by sizes, but by mixing them together, you can create more areas for the water to flow. The main point with the media is to have it be porous material and not packed together such that it can end up blocking water flow.

Cool thanks for the info. I found this tread by accident and there is a lot of good information. Im going to build mine tomorrow for my 300 gal FOWLR