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

[Feet4Fish]

Hi Ponraj quick update
Display tank is currently at 10ppm nitrate, efluent varies from 0ppm to 8ppm depending on the dosing, 2 hr after dosing it test 0ppm, after 6 hr nitrate start raising to 8-9ppm, current flow is 120 liter per day, currently dosing 4ml in the morning and 4ml in the evening, what can I do to have steady nitrates on the effluent?
Thanks

My suggestion would be utilize a dosing pump and spread out your 8 ml over 24 one hour doses.

 

[Tmmste]

So I made a mistake by attempting to guide the waterstream via a piece of airline tubing stuck inside the outflow of the reactor. Result; buildup of bacteria blocked the outflow.. flow stagnated and in the course of days stopped and eventually the pressure overflowed the reactor on the inlet. I frankly was building a smaller version to fit in the sump when this happened. So I emptied the reactor.. the smell was horrible.. hydrogen sulfide.

Does anyone know if the affected media is still useable / how to clear it from the hydrogen sulfide.

I am going use a skimmer again along with the reactor.. the water becomes very yellow within 1 week after removing the GAC. I do use a large powerfilter (3000lph) to remove small particulates, but it clogs fast due to the bacterial build-up on the filterwool. The proteinskimmer will lower the amount of carbon I need to dose and also skim the bacteria. hopefully this will make the bacterial buildup on the filterwool also less.

 

[Ponraj A]

Hi Ponraj quick update
Display tank is currently at 10ppm nitrate, efluent varies from 0ppm to 8ppm depending on the dosing, 2 hr after dosing it test 0ppm, after 6 hr nitrate start raising to 8-9ppm, current flow is 120 liter per day, currently dosing 4ml in the morning and 4ml in the evening, what can I do to have steady nitrates on the effluent?
Thanks

may be you can try with a dosing by splitting the 8ml dosage to 1ml every 3hrs. I think it keep the NO3 steady from the reactor

 

[Ivan L]

So I made a mistake by attempting to guide the waterstream via a piece of airline tubing stuck inside the outflow of the reactor. Result; buildup of bacteria blocked the outflow.. flow stagnated and in the course of days stopped and eventually the pressure overflowed the reactor on the inlet. I frankly was building a smaller version to fit in the sump when this happened. So I emptied the reactor.. the smell was horrible.. hydrogen sulfide.

Does anyone know if the affected media is still useable / how to clear it from the hydrogen sulfide.

I am going use a skimmer again along with the reactor.. the water becomes very yellow within 1 week after removing the GAC. I do use a large powerfilter (3000lph) to remove small particulates, but it clogs fast due to the bacterial build-up on the filterwool. The proteinskimmer will lower the amount of carbon I need to dose and also skim the bacteria. hopefully this will make the bacterial buildup on the filterwool also less.

My efluent is 3/4 inch pcv pipe and it s barely enough for not getting clogged

 

[Tmmste]

Did anyone try adding steelwool to the outflow of the reactor for Po4 binding? I wonder if the low flow through the reactor helps release small amounts of iron into the watercolumn. I drilled holes in the tube to prevent bacteria mulm blocking the exit.

 

[Darsh]

I've read this thread from start to finish in my free time over the last week. Really interesting and what a great idea! Also, what a tragic end to the creator Donovan, he seemed like a really nice guy, answering everyone's questions and helping them with their DND's. My heart goes out to his family.
Has anyone tried this with a smaller diameter pipe? For example, 2 inches? I think there might be a higher chance of blockage but Donovan had good success in stopping dosing for a few days when his reactor clogged.
My tank plus sump will only be slightly over 100L /25G so size-wise I think it should be okay, anyone think it's a bad idea?

 

[Ivan L]

I've read this thread from start to finish in my free time over the last week. Really interesting and what a great idea! Also, what a tragic end to the creator Donovan, he seemed like a really nice guy, answering everyone's questions and helping them with their DND's. My heart goes out to his family.
Has anyone tried this with a smaller diameter pipe? For example, 2 inches? I think there might be a higher chance of blockage but Donovan had good success in stopping dosing for a few days when his reactor clogged.
My tank plus sump will only be slightly over 100L /25G so size-wise I think it should be okay, anyone think it's a bad idea?

I do think that the reactor volume defines the flow rate, for example my reactor holds 10 litter of water, themost efficient flow rate that I have found is 6 liter per hour, it takes 1 hour and 40 minutes for water to make it trough the reactor which is plenty enough time for bacteria to consume oxigen and get 0 nitrates on the effluent.
So if you build a 2" reactor just calculate the volume and make sure it takes 1 to 2 hours for water to go trough. it should work the same.
Let me know if that helps

 

[Darsh]

I do think that the reactor volume defines the flow rate, for example my reactor holds 10 litter of water, themost efficient flow rate that I have found is 6 liter per hour, it takes 1 hour and 40 minutes for water to make it trough the reactor which is plenty enough time for bacteria to consume oxigen and get 0 nitrates on the effluent.
So if you build a 2" reactor just calculate the volume and make sure it takes 1 to 2 hours for water to go trough. it should work the same.
Let me know if that helps

Great thanks! I think that as long as I can keep the narrow reactors from clogging I should get good results :)

 

[FlyPenFly]

Basically a canister filter

 

[gregkn73]

Basically a canister filter

Basically not at all

 

[ducks4rob]

What pump are you guys using to run this? I have built one but I am using a cheap Amazon Homasy pump. Rated at 80gph max. I can regulate it to get a slow enough flow rate. Either it is too fast, or the pump is not strong enough to move the water through the reactor. It is 3" pipe 20" high. Filled with bio rings and bio balls.

 

[FlyPenFly]

How is it not? It's layered media and you insert a carbon source into the intake pipe/hose which is easily done.

 

[Darsh]

How is it not? It's layered media and you insert a carbon source into the intake pipe/hose which is easily done.

I don't think it would be so easy to just take an off the shelf canister filter and restrict the flow enough to allow the media, bacteria and carbon to do their job as efficiently as in this design.
But if you mean build a canister filter for this purpose then I suppose it meets the requirements to be called a "canister filter".

 

[FlyPenFly]

I think you can just use a DC pump to finely tune flow control. You can dose carbon into the intake of the pump or build something fancier into the feed line.

Otherwise, the newest canister filters would be a lot easier to maintain and give you a lot more sump space...


Just fill the media trays with Seachem Denitrate and Matrix. Maybe some ceramic media balls...

 

[Darsh]

I think you can just use a DC pump to finely tune flow control. You can dose carbon into the intake of the pump or build something fancier into the feed line.

Otherwise, the newest canister filters would be a lot easier to maintain and give you a lot more sump space...

Maybe. I suppose someone will have to test it out so we know for sure :)

 

[gregkn73]

I think you can just use a DC pump to finely tune flow control. You can dose carbon into the intake of the pump or build something fancier into the feed line.

Otherwise, the newest canister filters would be a lot easier to maintain and give you a lot more sump space...


Just fill the media trays with Seachem Denitrate and Matrix. Maybe some ceramic media balls...

My Donovan reactor has a total length, of 160cm and 12lt total volume. If you can find a canister filter with the above characteristics.....then you are right :-)

 

[Ivan L]

I think you can just use a DC pump to finely tune flow control. You can dose carbon into the intake of the pump or build something fancier into the feed line.

Otherwise, the newest canister filters would be a lot easier to maintain and give you a lot more sump space...


Just fill the media trays with Seachem Denitrate and Matrix. Maybe some ceramic media balls...

By looking at the bio media volume in the picture, you might make it work at a flow rate of 1 drop every 20 seconds or so

 

[FlyPenFly]

Don't get me wrong, I don't plan to do it. I think just a simple internal reactor with a dedicated carbon doser at the inlet is probably better for a reef tank unless I want to get a huge canister full of some kind of bio media. I prefer to use algae reactors for nutrient export but this is an intriguing idea. There is some evidence that bacteria also feeds corals but who knows if we're culturing the right kind.

 

[Tmmste]

Don't get me wrong, I don't plan to do it. I think just a simple internal reactor with a dedicated carbon doser at the inlet is probably better for a reef tank unless I want to get a huge canister full of some kind of bio media. I prefer to use algae reactors for nutrient export but this is an intriguing idea. There is some evidence that bacteria also feeds corals but who knows if we're culturing the right kind.

Tried both. Had good results with an ATS. needed cleaning though, makes noise when it clogs with algae, and managed to kill the algae a number of times (too much light.. forgot to clean the screen). The DND needs some vinegar and that is about it.. no maintenance and works much faster for reducing No3. Regarding "There is some evidence that bacteria also feeds corals but who knows if we're culturing the right kind": DyMiCo.

 

[Tmmste]

Update: So I have been using (Metalino) steelwool in the outflow of the DND (donovans nitrate destroyer), drilled some holes in the tubing. just in case the waterflow is restricted due to clumping of the rust. To prevent a build up of rust in equipment, I am filtering over filterwool (fiberfill - dacron). So far it has been serving me well. 0,8 grams of steel wool binds 0,04 ppm Po4 of my 400L tank. Due to the low flow of the output it prevents clouding in the tank and the rusted steel remains in the tube (loosely), and is easy to flush out in the sink and replace with some fresh steel.

Who knows, maybe it helps those struggle with rising Po4. Steel wool is incredibly effective in binding Po4... and very cheap too.. i would say a nice addition to this poor man nutrients control.