Remove 0.2 minimum difference requirement in pH input range

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Reefbeta

Reefbeta

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As explained in my other thread, I need the ability to turn stuff on/off on a single pH point, like on when above 8.3, and off when below 8.3. Not on when above 8.3, and off when below 8.1. The 0.2 difference is too big for the experiment I want to run.
 
Thank you for your suggestion. The .02 prevents things like a solenoid from turning ON/OFF constantly when the reading is at the threshold and damage the solenoid. We will definitely consider it.
 
My guess that was the reason. But I think using the minimum on/off time setting is a much better way to protect the solenoid.
 
I read both of you're thread's, and I'm agree with you. Also I was above to do the same experiment, add a solenoid to control the usage of Co2 scrubber trying to maintain a pH of 8.3.

Usually the average of my pH is 8.25 during the period of lights On. 2 hours before the lights goes on my ph drops to 8.02 to 8.09.

With this window of setting the minimum and maximum of .2 will be useless to add the solenoid because I will have the same variation.

It will be very helpful if the range of the pH control can be reduced to .05, it is pretty understandable that the life of the valve will be reduced. This decision will be fom the user to use it or not.
 
Yeah I’ve been racking my brain on a way to achieve a smaller hysteresis by using the logic already provided by the logic of hydros but I can’t figure it out. But yeah I agree a 0.1 window seems reasonable.
 
It would be trivial for us to remove this offset, but I wanted to explain a bit about it and get your opinion if we really want to do this.

Lets take the example of 8.0 and 8.2 for the two values. Since we have .1 pH resolution here this means that:
  • pH lower than 8.05 will turn the device on.
  • pH between 8.05 and 8.15 will leave it alone.
  • pH above 8.15 will turn it off.
So the hysteresis range is actually between 8.05 and 8.15 when you take proper rounding into account.

When you consider that the basic accuracy of all affordable probes are only +/- 0.1 pH, this is a pretty narrow range.

If we allowed the range to come down to 0.1 then the following would happen, suppose your values are 8.0 and 8.1
  • pH lower than 8.05 will turn the device on.
  • pH above 8.05 will turn it off.
This would eliminate the hysteresis entirely.

Let me know what you think.
 
Don said:
It would be trivial for us to remove this offset, but I wanted to explain a bit about it and get your opinion if we really want to do this.

Lets take the example of 8.0 and 8.2 for the two values. Since we have .1 pH resolution here this means that:
  • pH lower than 8.05 will turn the device on.
  • pH between 8.05 and 8.15 will leave it alone.
  • pH above 8.15 will turn it off.
So the hysteresis range is actually between 8.05 and 8.15 when you take proper rounding into account.

When you consider that the basic accuracy of all affordable probes are only +/- 0.1 pH, this is a pretty narrow range.

If we allowed the range to come down to 0.1 then the following would happen, suppose your values are 8.0 and 8.1
  • pH lower than 8.05 will turn the device on.
  • pH above 8.05 will turn it off.
This would eliminate the hysteresis entirely.

Let me know what you think.
Click to expand...
That wouldn't fall into an endless cycle?

If im trying to set my ph to 8.25-8.35, I will use Co2 scrubber with the solenoide valve this means:
  • pH lower than 8.25 will turn the device on.
  • pH above 8.35 will turn it off.
here is my range of .1 can we add a delay of 30-50 seconds to avoid the smal variations and reduce the action of the solenoide?

will work?
 
Abraham04 said:
That wouldn't fall into an endless cycle?

If im trying to set my ph to 8.25-8.35, I will use Co2 scrubber with the solenoide valve this means:
  • pH lower than 8.25 will turn the device on.
  • pH above 8.35 will turn it off.
here is my range of .1 can we add a delay of 30-50 seconds to avoid the smal variations and reduce the action of the solenoide?

will work?
Click to expand...
Yes, just use the min on and min off times for this.
 
Don said:
It would be trivial for us to remove this offset, but I wanted to explain a bit about it and get your opinion if we really want to do this.

Lets take the example of 8.0 and 8.2 for the two values. Since we have .1 pH resolution here this means that:
  • pH lower than 8.05 will turn the device on.
  • pH between 8.05 and 8.15 will leave it alone.
  • pH above 8.15 will turn it off.
So the hysteresis range is actually between 8.05 and 8.15 when you take proper rounding into account.

When you consider that the basic accuracy of all affordable probes are only +/- 0.1 pH, this is a pretty narrow range.

If we allowed the range to come down to 0.1 then the following would happen, suppose your values are 8.0 and 8.1
  • pH lower than 8.05 will turn the device on.
  • pH above 8.05 will turn it off.
This would eliminate the hysteresis entirely.

Let me know what you think.
Click to expand...
This is unexpected and not match of what I see. The graph of pH has 0.01 resolution. I'm looking at it, my current pH is 8.28. I have an outlet with 8.1 to 8.3, ON when pH high. But that outlet is not ON. So it appears that it's actually working on the 0.01 resolution. The only things that have 0.1 resolution limit are the adjustment bars to set pH values.
 
In the livestream with reefdudes announcing Control 3, I noticed the minimum difference of pH in the demo is 0.1. Carlo can set pH points of CaRx to 6.9 and 7.0. Is it a change in the dev version? Will it be included in the next firmware update?
 
Reefbeta said:
In the livestream with reefdudes announcing Control 3, I noticed the minimum difference of pH in the demo is 0.1. Carlo can set pH points of CaRx to 6.9 and 7.0. Is it a change in the dev version? Will it be included in the next firmware update?
Click to expand...
Updated this week:
129E7AB8-2CF2-40A6-AD5C-6EE3EA452207.jpeg
 
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