DeNITRIFIER Midwest Aquatics or Aquamedic

[catman78]

Anyone running these?
if so, which one?

Midwest users; Sulfur DeNITRIFIER or DeNITRIFIER?

Do you run it with ORP monitor or not?

Any input would help

Thanks
Mark

[ari5736]

Curious as to why and how you would run with ORP controller.

[Aquaticadvisor]

I have a sulfur version.....This is plug and play.... Within a couple of days it was working. You do not need a orp monitor with this unit.

[Bruno3047]

With an ORP monitor, you don't have to constantly be running nitrate and nitrite tests to tell if your denitrator is working or not, and what adjustments, if any, need to be made to the flow rate.

[ChuckLawson]

I've been considering adding a sulfur reactor -- what specifically are you watching in ORP as an indicator? Just a general decline in redox?

[Bruno3047]

Yes. Basically, by watching the redox level inside the reactor, you can accurately determine what the situation is regarding the denitrification process.

As the oxygen inside the reactor is used up, which must happen before any denitrification can take place, redox levels will fall.

Without getting into the science behind it, once the redox level falls below -50mv, denitrification begins to take place. You want to keep the redox range inside the reactor between -100mv and -250mv. A drop below -300mv will cause the reduction of the sulfur inside the reactor to hydrogen sulfide, which is accompanied by a "rotten egg" smell. This can be poisonous to your animals in high enough concentrations.

The adjustment in the flow rate is that as redox levels approach -250mv, you want to increase the flow rate. As it climbs towards -50mv, you want to decrease the flow rate.

By using an ORP monitor in this way, you can adjust the flow rate to achieve denitrification inside the reactor without the constant testing and re-testing for nitrite and nitrate.

Unfortunately, most of the commercial denitrators do not have a port built-in for an ORP probe.

[ari5736]

very interesting

[catman78]

Thanks for clarifying Bruno3047.

The Aqua-Medic does have a port for probe.
http://www.aqua-medic.com/products/d...uctor_1000.pdf

I've seen the Nitrate_Reductor_1000 for as little as $245.

Orp probe and controller would be extra.

Thanks

[ChuckLawson]

Originally posted by Bruno3047
Yes. Basically, by watching the redox level inside the reactor, you can accurately determine what the situation is regarding the denitrification process.

As the oxygen inside the reactor is used up, which must happen before any denitrification can take place, redox levels will fall.

Without getting into the science behind it, once the redox level falls below -50mv, denitrification begins to take place. You want to keep the redox range inside the reactor between -100mv and -250mv. A drop below -300mv will cause the reduction of the sulfur inside the reactor to hydrogen sulfide, which is accompanied by a "rotten egg" smell. This can be poisonous to your animals in high enough concentrations.

The adjustment in the flow rate is that as redox levels approach -250mv, you want to increase the flow rate. As it climbs towards -50mv, you want to decrease the flow rate.

By using an ORP monitor in this way, you can adjust the flow rate to achieve denitrification inside the reactor without the constant testing and re-testing for nitrite and nitrate.

Unfortunately, most of the commercial denitrators do not have a port built-in for an ORP probe.

Interesting! I wasn't thinking about having the probe in the reactor itself, but that makes a lot of sense. I take it you run (or have ran) a system like this? How often do you have to maintain the probe, and how do you do it without introducing O2 into the system?

Thanks!

[moondoggy4]

Very interesting tagging along

[bimmerzs]

catman,

I use midwest's sulfur denitrator. Setup was very easy, just follow the included direction's and you will be good to go.

Cheers,