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

[olonmv]

Ok now I'm confused. I saw earlier that you should shoot for a dwell time of an hour or sow. If that's the case 1 GPH is equal to 63 ml/min. 10% of my volume per hour would be 17 ml/min so much slower. If the concentration of nitrates is fixed at let's say 100ppm does it really matter what the volume is? 10 gallons at 100ppm is the same concentration as 100 gallons at 100ppm wouldn't it just bring them down faster in the smaller volume?

What is your water volume?

 

[legionofdoon]

I'm estimating around 65. But regardless if the reactor can process the nitrates at a given dwell time does the tank volume even matter at that point besides maybe too quickly dropping the nitrates?

 

[olonmv]

Assuming 65 gallons, you should turn over 6.5 gallons per day….also assuming your DND is built to proportion of your tank, 17ml per minute sounds about right. How much carbon are you dosing?

 

[legionofdoon]

I'm still building it.

 

[olonmv]

If you build it to size for your tank volume follow the process Donovan lays out in the beginning. That’s how I did. Best of luck!

 

[legionofdoon]

I'm using 50 inches of 3 in tube.

 

[legionofdoon]

Here's mine completely cycling with tank water.

 

[legionofdoon]

3 inch PVC at 56 inches submerged so 1.7 gallons, push to connect fittings with unseals. No leaks after 3 days. Currently outside of sump but once dialed I'm thinking of pulling the chaeto out and placing this is the refugium area. Kinda hard dialing in flow with current valve so just bought a needle valve from aquacave. Also used 5l of AF biofil and 2l of ceramic pyramids from box tech (I think it was box tech) first chamber is a mix but mostly the larger pieces and second chamber apart from the base is bio fil. Added vodka second day via X1 doser at 2 ml per day over 24 hours water in the bucket is cloudy so hopefully bacteria is starting to grow. Figured recirculating that cloudy water will speed the seeding of the ceramic media. Will check nitrates next week and hopefully put it permanently on line then. Any suggestions?

 

[olonmv]

3 inch PVC at 56 inches submerged so 1.7 gallons, push to connect fittings with unseals. No leaks after 3 days. Currently outside of sump but once dialed I'm thinking of pulling the chaeto out and placing this is the refugium area. Kinda hard dialing in flow with current valve so just bought a needle valve from aquacave. Also used 5l of AF biofil and 2l of ceramic pyramids from box tech (I think it was box tech) first chamber is a mix but mostly the larger pieces and second chamber apart from the base is bio fil. Added vodka second day via X1 doser at 2 ml per day over 24 hours water in the bucket is cloudy so hopefully bacteria is starting to grow. Figured recirculating that cloudy water will speed the seeding of the ceramic media. Will check nitrates next week and hopefully put it permanently on line then. Any suggestions?

Sounds like you’re well on your way!!! Keep an eye on flow. Mine was drips worth of flow. I used a metronome to set the rhythm of the drip.

 

[legionofdoon]

Drops per minute or drops per second? I've used a measuring cup and graduated cylinders and got it set up now for 1.5 hours dwell time. The problem is when I decrease that rate it seems to pull in air from the discharge, I may need to add a check valve on it.

 

[olonmv]

Drops per minute or drops per second? I've used a measuring cup and graduated cylinders and got it set up now for 1.5 hours dwell time. The problem is when I decrease that rate it seems to pull in air from the discharge, I may need to add a check valve on it.

I average about 43 drops per minute. Mine is fed via a small pond pump. It’s always on so I always has positive pressure. I constantly had to tweak the valve but my pressure never fed back. Is your setup gravity fed or pump driven?

 

[legionofdoon]

Pump driven I just time it using a graduated cylinder it takes 2.5 hours for the water to pass through mine.

 

[legionofdoon]

Also I think it's nitrogen bubbles in the discharge I don't see any thing being pulled back up and before I slowed it down it was producing a lot of bubbles I may need to make the discharge tube smaller

 

[olonmv]

Pump driven I just time it using a graduated cylinder it takes 2.5 hours for the water to pass through mine.

Not sure what travel time for your dnd is but sounds about right.

Also I think it's nitrogen bubbles in the discharge I don't see any thing being pulled back up and before I slowed it down it was producing a lot of bubbles I may need to make the discharge tube smaller

I think it’s too soon for the nitrogen bubbles if you in fact ever get them…I never did and we speculate it’s because in my setup there’s no where for nitrogen to get trapped and accumulate. Same may be as well for you.

 

[legionofdoon]

I started with bio fill it's preseeded with bacteria and shipped wet.

 

[legionofdoon]

Output is at zero running in a bucket. Putting it in the sump Tomorrow, so it took 10 days for mine to cycle. The output turned super high about 3 days before it started to test zero which I assume was nitrites interfering.

 

[legionofdoon]

Placed it in the tank. Output no longer zero. Flow is 17 ml per minute. Hopefully it comes back online soon

 

[legionofdoon]

Got the egg smell, but nitrates still tested at 25. Increased the flow. One thing I had to figure out was the exit tube, since it was so slow would pull air back into the second chamber. I remedied this hopefully by pointing the discharge upwards. Never got the sulfur smell until I did that. Anyone have any other suggestions?

 

[legionofdoon]

Glad I have one of these to double check. Using the Salifert test and my less than stellar color vision I was testing at 10-25. This is the output. I finally got it dialed in. Mine is running 30 ml/min.

 

[legionofdoon]

So little over a month to start working.