All about Denitrator

Originally Posted by WaterZoo

Bro .. no offence as I think you need to re-examine why 1 unit of 1m tall denitrator can't able to reduce your tank nitrate level to 25ppm.

In fact, it should be able to get less than 10ppm.

Maybe I can explain.

Tank
- very high bioload. Around 25 mg/l of NO3 per week.
- very efficient bio-conversion filtration system. DOC low.

Denitrator
- insufficient carbon-source supply
- controlled by ORP denitrator (set at -200mV to kick in). The interval between kicking in ....too long.
- overall estimated flowrate out from denitrator ....about 5 l/hr.

His tank volume of more than 1000 litres. The denitrator running at
4 l/hr, it will take more than 8 days to complete 1 turnover whereas the NO3 is generating at 25 mg/l per week.

Simple solution. Increase feeding on the denitrator.

In my opinion, he will have the same problem even with an additional unit as it takes months for a carbon-fed denitrator to completely produce zero nitrate.

Fyi, it took about 4 months for a NR1000 with 40 pcs of deniballs to churn out 10 ppm for a 1000 litres of tank capacity with two feedings consisting of 20 cubes of brine/mysis shrimp.

Suggest to do 10% partial water changes on a weekly basis to compensate for feeding and also the build-up of nitrate due to DOC. By doing this, it will helps to improve on the denitrator's efficiency.

Originally Posted by WaterZoo

In my opinion, he will have the same problem even with an additional unit as it takes months for a carbon-fed denitrator to completely produce zero nitrate.

Fyi, it took about 4 months for a NR1000 with 40 pcs of deniballs to churn out 10 ppm for a 1000 litres of tank capacity with two feedings consisting of 20 cubes of brine/mysis shrimp.

Suggest to do 10% partial water changes on a weekly basis to compensate for feeding and also the build-up of nitrate due to DOC. By doing this, it will helps to improve on the denitrator's efficiency.

Point noted. FYI, the setup was done by me and for experiemental purposes. Bro Octane was kind enough to allow me to use it on his tank.

The purpose of this experiment is:

- can DOC be sufficient without resorting to feeding.
- testing the efficiency of various carbon source
- flowrate of denitrator vs bioload of tank vs tank volume

As I am building another denitrator ( because I am not that pleased with the current version), octane is willing to provide test bed which explain for the 2 tall denitrators.

Originally Posted by WaterZoo

In my opinion, he will have the same problem even with an additional unit as it takes months for a carbon-fed denitrator to completely produce zero nitrate.

Fyi, it took about 4 months for a NR1000 with 40 pcs of deniballs to churn out 10 ppm for a 1000 litres of tank capacity with two feedings consisting of 20 cubes of brine/mysis shrimp.

Suggest to do 10% partial water changes on a weekly basis to compensate for feeding and also the build-up of nitrate due to DOC. By doing this, it will helps to improve on the denitrator's efficiency.

To find out how long it would take to lower your nitrate level by using water changes, assuming no further build up of nitrate which is very unlikely, simply find your current nitrate level on any of the three plots.

Follow a plot to the target level to find the number of changes required ie with 10%, 25% or 50% water changes and double click on the graph for a larger view.

Hope this info helps.

Very good chart, mod Sunburst! The chart is based on a fixed 20 mg/l of NO3 only. In real case scenario, the NO3 is constantly generated because of bio-conversion which complicates the issue further. This is precisely the reason on why standard WC (20% once a week) can never control the level of NO3 even for a normal tank without addtional means.

Another informative source on WC vs NO3 is using the calculator from practicalfishkeeping but must sign in first.

Originally Posted by atom

Very good chart, mod Sunburst!
Another informative source on WC vs NO3 is using the calculator from practicalfishkeeping but must sign in first.

Thanks for the link.

Good info regarding water changes contributed by Mod Sunburst and Bro Atom.

[octane]

Originally Posted by WaterZoo

In my opinion, he will have the same problem even with an additional unit as it takes months for a carbon-fed denitrator to completely produce zero nitrate.

Fyi, it took about 4 months for a NR1000 with 40 pcs of deniballs to churn out 10 ppm for a 1000 litres of tank capacity with two feedings consisting of 20 cubes of brine/mysis shrimp.

Suggest to do 10% partial water changes on a weekly basis to compensate for feeding and also the build-up of nitrate due to DOC. By doing this, it will helps to improve on the denitrator's efficiency.

weekly water change of 20% with treated age water containing minute ammonia and zero nitrate. as mentioned, nitrate is produced too fast for denitrator to handle. currently still feeding on 5ml sugar solution daily.

[octane]

Originally Posted by WaterZoo

In my opinion, he will have the same problem even with an additional unit as it takes months for a carbon-fed denitrator to completely produce zero nitrate.

Fyi, it took about 4 months for a NR1000 with 40 pcs of deniballs to churn out 10 ppm for a 1000 litres of tank capacity with two feedings consisting of 20 cubes of brine/mysis shrimp.

Suggest to do 10% partial water changes on a weekly basis to compensate for feeding and also the build-up of nitrate due to DOC. By doing this, it will helps to improve on the denitrator's efficiency.

Originally Posted by atom

Point noted. FYI, the setup was done by me and for experiemental purposes. Bro Octane was kind enough to allow me to use it on his tank.

The purpose of this experiment is:

- can DOC be sufficient without resorting to feeding.
- testing the efficiency of various carbon source
- flowrate of denitrator vs bioload of tank vs tank volume

As I am building another denitrator ( because I am not that pleased with the current version), octane is willing to provide test bed which explain for the 2 tall denitrators.

it's more than willing

Come back to basics. Atom, the solenoid valve and the ORP controller, how does it work?