There has been very much post claiming that GHL software is crap. I´m not one of those that think so - instead it is very well done. With help of both P3.x and P4 I have been able to solve very difficult problems with controlling different processes. In an earlier experiment with coral growth and acidification I succeeded to control pH with less than 0.02 swing. From 7.6 to 8.4 as wanted pH. This included a daily rise with 0.2 units during 12 hours - when back to the nominal value. In my own aquarium I have a 25 cm thick DSB. In the bottom of that DSB - it is an old undergravel filter with 4 tubes up to the surface. One of the tubes is the inlet for water that is pumped under the undergravel filter - creating a reversed flow up though the sand bed. In another tube I have a redox electrode - measuring the redox in the water below the DSB - and in another - there is a pH probe measure the pH in the poor water below the sand bed. There is also a tube for ethanol feed below the sandbed.
The general idea is to have an anaerobic environment below the sandbed (and up in the sandbed) feed water for the circulation and ethanol for denitrification and to uphold a low redox potential. Wanted is between -150 to -200 mV. But as soon as I pump surface water - from the refugium - i get in oxygen and the redox will rise (and need more ethanol in order to decrease afterwards) The trick is to balance these flows so it give you a disent flow of water through the sand bed but still a low redox potential (i.e anaerobic environment) I decided to use my redox probe as the main controller for this but I needed two different nominal values (one for the waterpump and one for the ethanol pump) The start of this whole adventure was to create a virtual copy of my physical redox probe below the sand bed. In my case Redox 5 is the physical and Redox 1 is my virtual probe. Redox 1 control my addition of ethanol (DOC) and redox 5 control my water pump
Here you can see that I have two different nominal values (I have tested out these nominal values for my set up - can be different in other set ups
Below you can see the real power - GHL has not only an on/off mode - it has more control modes. Here I have used pulse variable for my ethanol pump and pause variable for my water pump. For my ethanol pump - max pulse is 25 sec and a fixed pause on 30 minutes. This means that the controller analyze how large the deviation from the nominal value you are. with help of this it decide how long time (from 0 to 25 sec) the pump should run. After this - it wait for 30 minutes and after that do a new analyze and the new running time will be 0, shorter or longer than the last run - if the deviation is larger - run more, if it lower run les and if it is 0 or that the real value is (in this case when the run should decrease down to the nominal value) is lower than the nominal value + 1/2 hysteresis - it happens nothing - after 30 minutes a new analyze,
For my water pump - I have chose pause variable and max pause 45 minutes - fixed pulse 8 sec This means that the program analyse with help of the deviation from the nominal value how long the paus should be (between 0 and 45 minutes) - after that a fixed pulse of 8 sec, new analyze and new variable pause. In this case - the action should increase the redox potential - therefore if the redox hit the nominal value +1/2 hysteresis - nothing happens
OK - the controllers is fixed - now we have to knit one to a working outlet (switch) - In my case it is Switch 3 (for my pump below the DSB) Redox 5 control upwards (increase). This is a real outlet - I connect my water pump here (max 300 L/h but measured to 120 L/H (2000ml/minute))
My addition of ethanol is managed by a pump head of one of my doser 2. To have this to work we need to knit an virtual switch (no physical outlet) to redox 1 control downwards (decrease) I chose switch 60
For the ethanol we need to knit to a real doser head - in my case pump 12. Calibrate - and I run it slow (1). I knit it to switch channel 60 and switch on recording. Every time switch 60 is on - the pump will run as long as switch 60 is on.
In order to record how much water my water pump runs - I create a virtual dosing pump (one that´s not in physical use. P4 have 32 pumps available - I chose pump head 30. My water pump was clocked to 120 L/H -> 2000 ml/minute. You can´t use 2000 ml/minute as calibration amount - I chose to use 20 ml/minute and have to remember to always multiplicate the result with 100. Mark recording and chose switch index 3 (the water pump) Everytime this switch run - you will record the amount / 100
Now to the results I have got. During long time I was pleased with a switch of ± 30 mV and lower flow but all of this talk about crappy software get me a little bit upset and I decided to see what this crappy software can do- The result since yesterday
Since this morning - the deviation have been 1 mV !!!!!!!!!!!. Before it was 3 mV. I have use around 18 ml 8% ethanol (DOC) and pumped around 500 L aquarium water through the sand bed. My nitrate level is around 5 and I will see what will happens with this during the coming days. I have not change water for more than 4 years.
I will stress once again - people that talk about crappy GHL software - do not know what they are talking about. The software help you to program very complicated relationship in a way that I can hold a deviation of 1 mV in my poor water below the DSB. I know competitors that not even manage to read negative redox potential if you do not do a physical fix. .
The redox potential and the redox probe is useful according to manage anaerobic environment - not so useful in open water if you do not run ozone - by the way - the water that is pumped in below the DSB have this ORP profile
Sincerely Lasse
The general idea is to have an anaerobic environment below the sandbed (and up in the sandbed) feed water for the circulation and ethanol for denitrification and to uphold a low redox potential. Wanted is between -150 to -200 mV. But as soon as I pump surface water - from the refugium - i get in oxygen and the redox will rise (and need more ethanol in order to decrease afterwards) The trick is to balance these flows so it give you a disent flow of water through the sand bed but still a low redox potential (i.e anaerobic environment) I decided to use my redox probe as the main controller for this but I needed two different nominal values (one for the waterpump and one for the ethanol pump) The start of this whole adventure was to create a virtual copy of my physical redox probe below the sand bed. In my case Redox 5 is the physical and Redox 1 is my virtual probe. Redox 1 control my addition of ethanol (DOC) and redox 5 control my water pump
Here you can see that I have two different nominal values (I have tested out these nominal values for my set up - can be different in other set ups
Below you can see the real power - GHL has not only an on/off mode - it has more control modes. Here I have used pulse variable for my ethanol pump and pause variable for my water pump. For my ethanol pump - max pulse is 25 sec and a fixed pause on 30 minutes. This means that the controller analyze how large the deviation from the nominal value you are. with help of this it decide how long time (from 0 to 25 sec) the pump should run. After this - it wait for 30 minutes and after that do a new analyze and the new running time will be 0, shorter or longer than the last run - if the deviation is larger - run more, if it lower run les and if it is 0 or that the real value is (in this case when the run should decrease down to the nominal value) is lower than the nominal value + 1/2 hysteresis - it happens nothing - after 30 minutes a new analyze,
For my water pump - I have chose pause variable and max pause 45 minutes - fixed pulse 8 sec This means that the program analyse with help of the deviation from the nominal value how long the paus should be (between 0 and 45 minutes) - after that a fixed pulse of 8 sec, new analyze and new variable pause. In this case - the action should increase the redox potential - therefore if the redox hit the nominal value +1/2 hysteresis - nothing happens
OK - the controllers is fixed - now we have to knit one to a working outlet (switch) - In my case it is Switch 3 (for my pump below the DSB) Redox 5 control upwards (increase). This is a real outlet - I connect my water pump here (max 300 L/h but measured to 120 L/H (2000ml/minute))
My addition of ethanol is managed by a pump head of one of my doser 2. To have this to work we need to knit an virtual switch (no physical outlet) to redox 1 control downwards (decrease) I chose switch 60
For the ethanol we need to knit to a real doser head - in my case pump 12. Calibrate - and I run it slow (1). I knit it to switch channel 60 and switch on recording. Every time switch 60 is on - the pump will run as long as switch 60 is on.
In order to record how much water my water pump runs - I create a virtual dosing pump (one that´s not in physical use. P4 have 32 pumps available - I chose pump head 30. My water pump was clocked to 120 L/H -> 2000 ml/minute. You can´t use 2000 ml/minute as calibration amount - I chose to use 20 ml/minute and have to remember to always multiplicate the result with 100. Mark recording and chose switch index 3 (the water pump) Everytime this switch run - you will record the amount / 100
Now to the results I have got. During long time I was pleased with a switch of ± 30 mV and lower flow but all of this talk about crappy software get me a little bit upset and I decided to see what this crappy software can do- The result since yesterday
Since this morning - the deviation have been 1 mV !!!!!!!!!!!. Before it was 3 mV. I have use around 18 ml 8% ethanol (DOC) and pumped around 500 L aquarium water through the sand bed. My nitrate level is around 5 and I will see what will happens with this during the coming days. I have not change water for more than 4 years.
I will stress once again - people that talk about crappy GHL software - do not know what they are talking about. The software help you to program very complicated relationship in a way that I can hold a deviation of 1 mV in my poor water below the DSB. I know competitors that not even manage to read negative redox potential if you do not do a physical fix. .
The redox potential and the redox probe is useful according to manage anaerobic environment - not so useful in open water if you do not run ozone - by the way - the water that is pumped in below the DSB have this ORP profile
Sincerely Lasse
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