Maxi doser and profilux

[Dave-T]

I have a Maxi Doser 2.2, connected to an expansion box. Is it true that you can't access it/program it from GHL Connect through the Profilux? I have it connected to an expansion box, which is connected to my Profilux, but I don't see how to program it other than by connecting to it directly (which I haven't tried yet).

 

[Gaël]

Hello,

You have to set it as slave first:

How to switch SA Doser to EXT mode - GHL Advanced Technology

www.aquariumcomputer.com

Then you have to assign it to ProfiLux:

How to assign PAB-devices - GHL Advanced Technology

www.aquariumcomputer.com

Gaël

 

[Dave-T]

All set, thanks. So I'd like to use the maxi doser to do water changes. How do people do that? The easiest and most elegant way would be to tell the doser to remove x liters using one pump, and add the same amount with the other. Will that work? I'm not sure if I can trust the calibration of both pumps to be the same.

 

[Sisterlimonpot]

As long as you keep up with the calibration of the pumps you'll be fine...

Besides even if it was slightly off, you lose more in salinity swings with a protein skimmer.

 

[Dave-T]

As long as you keep up with the calibration of the pumps you'll be fine...

Besides even if it was slightly off, you lose more in salinity swings with a protein skimmer.

Thanks. So this is a common use for the Maxi doser - to do water changes as I talked about? I'm planning on doing 80 gallon - 25% per week water changes for the near term, so if the pump rates diverge, there could be significant salinity drift.

How frequently is recommended to recalibrate the pumps?

 

[Sisterlimonpot]

Thanks. So this is a common use for the Maxi doser - to do water changes as I talked about? I'm planning on doing 80 gallon - 25% per week water changes for the near term, so if the pump rates diverge, there could be significant salinity drift.

How frequently is recommended to recalibrate the pumps?

I'm not a GHL user but it's common for most peristaltic pumps to be recalibrate every 30 days.

From my experience after the peri tube has been broken in you can get away with longer intervals. But when using it for AWCs you're going to want them both to be fairly accurate.

As for the maxi being up to do water changes. Yes definitely well within the wheelhouse of this pump.

I personally use 2 ecotech versas and they run continuously changing 20% weekly. Some people prefer running them on a schedule, performing short tasks throughout the day. It comes down to preference and the capabilities of the pumps you're using.

@Gaël woule be able to provide specifics on how to program the pump. He is veey well versed in GHL equipment and has helped me in the past.

 

[Dave-T]

Ok, I'll get some graduated cylinders so I can do accurate calibration measurements, and plan on doing periodic recalibration until I get a sense of if/how calibration can diverge over time.

So I want to dose 43 liters/day to do my water changes. The GHL software doesn't seem to let me dose more than 3 liters at a time, which means that I'd need to put 15 entries in the dosing schedule, and also figure out how to space them apart so they don't run into each other. I'd prefer to dose all at once, all 43 liters. Is there a way to do that, @Gaël ?

 

[Gaël]

Ok, I'll get some graduated cylinders so I can do accurate calibration measurements, and plan on doing periodic recalibration until I get a sense of if/how calibration can diverge over time.

So I want to dose 43 liters/day to do my water changes. The GHL software doesn't seem to let me dose more than 3 liters at a time, which means that I'd need to put 15 entries in the dosing schedule, and also figure out how to space them apart so they don't run into each other. I'd prefer to dose all at once, all 43 liters. Is there a way to do that, @Gaël ?

Hello,

You can use automatic dosing:

Gaël

 

[Dave-T]

Yes, I can see that, but I'd prefer not to spread them throughout the day. What if I want to do it all at once? At least at first, I'd like to monitor it so I want to be there when it tries to do all 43 liters. Is there a reason for the 3000ml/dose limit, or is there a way to dose more than 3 liters at a time?

 

[Dave-T]

Gael - please let me know. Is there a reason for the 3 liter/dose limit? Should I worry about burning out the pumps or something if I try to schedule back-to-back doses so I can dose 43 liters all at once?

 

[Sisterlimonpot]

Gael - please let me know. Is there a reason for the 3 liter/dose limit? Should I worry about burning out the pumps or something if I try to schedule back-to-back doses so I can dose 43 liters all at once?

I can only speculate alongside you. Heat is a major factor with running stepper motors continuously, they require a lot of current to provide the torque to spin the rotor. Because of this some manufacturers build in cool down times in the software that prevents them from being used continuously or for long periods of time. This might just be the nature of the maxi pump.

I get the need to be around to watch the process to ensure everything is working properly. Perhaps waiting for the weekend to provide the time to monitor it's operation might be necessary.

 

[KenO]

There is a way around the system limit, let me think about it and do a little testing to see if my line of thinking works. I will post my results later today.

 

[KenO]

I am a long time P4 user and I do have a new Maxi 2.2.

With the new firmware there is now a setting right below the calibration setting. We will need this to make this work. Please note this new setting would also work with the Maxi 2.1.

So if I'm understanding correctly you want to do a single 43L water change. That number is too high for the system to let you do a single WC. There in lies the issue. So we just have to be smarter than the system.

Here is what I would do.

First do a calibration on both pumps.

I calibrate all my pumps using the following method. You will need a gram scale. I use my kitchen scale set to grams.

With all tubing in place on the Maxi doser, I run 5 calibrations in a row collecting all the water. I then weigh the water and divide the total by 5. Basically 1ml = 1 gram. It works and I've been doing it for years. I would calibrate using a level 2 or 3 for the pump if you want the time for the AWC to be shorter.

Let’s say you want do a 150ml/min dosing setup. To get that you would need to get a calibration of over 150ml/min.

Some math. If you take 43L (43000ml/150ml/min) = 287 min or 4.78 hours. Lets use this for our example.

You can go with a lower or higher number depending on how long you want the pumps to run.

Once the calibration is completed, set the desired flow to be 150ml. This is why the calibration has to be higher than the amount you want to set the desired speed to be. If you look at the image I uploaded my Max flow (determined by calibration) was 64.2ml/min. I set my desired flow to be 30ml/min. You can see I have a range of 20.8 to 64.2 that I can set this number to. There a max continuous flow, but I can't remember what that number is right now.

For this to work, both pumps have to have their desired flow set to the same number. So once you calibrate both pumps, make sure the desired flow is the same on both pumps.

The pumps can be set to follow a dosing schedule or switch channel. You will need to tell it to use a switch channel.

You will need to create a timer and tell the switch channel you picked to use that timer.

You will want to set the pumps to use the the same switch channel. You will then want to program a timer for the time to start and end to cover the 4.78 hours of our example. The system can have a maximum number of 64 switch channels. Assuming you don’t have 64 actual switch channels, if you pick something high up in the 60's, you will be creating a virtual switch channel which will control your pumps. Both pumps will use the same switch channel you created. That ensures each pump turns on and off at the same time. If you want the pumps to run at different times, you will need 2 timers and 2 switch channels. You can then set the water out to run first and then the water in to run once the water out timer is finished.

You will then need to tie the timer number you created to the switch channel. Just like you would program a light to come on and off with an actual physical switch channel the virtual switch channel works the same way. As far as the system is concerned it is turning on and off a switch channel.

Outside of the window of time you would want them to run the pumps will be off. When the timer comes true, the pumps will run at the continuous setting of 150ml. When the timer reaches it's stop time, the pumps will turn off.

Setting up the above will get around the system limits of a single dose. You can also pick what time of day or night to run the AWC.

Are you familiar with programing using timers and switch channels or did I lose you?

If I lost you, let me know I can post all the steps to make the above work.

 

[Sisterlimonpot]

Eek Ken,

I was lost but then again I'm not familiar with GHL. Hopefully @Dave-T gets it.

 

[Dave-T]

Thanks Ken. Yes, I'm totally with you. I know how to do what you're saying. When you started talking about calibration and being smarter, I thought you were going to say to tell the doser that the max speed dosing rate was much much less than it actually is - so tell it that it's 1/10 what the true calibrated dosing output was, and then when you tell it to dose 3000 ml, it would actually dose 30,000 ml. But that wasn't what you said. But maybe that would work too!

Anyway, I like your idea. I would still like to know if it's ill advised to dose that much all at once. My suspicion is that there is not a good reason for the max of the doser to be 3 liters per dose. But I don't want to assume that, maybe there is a good reason for it, like it could damage the pumps if you tried to dose more than 3L at a time. I'm still hoping Gael will weigh in.

I wonder what the dosing history would say, if you did it your way? An advantage of dosing all at once is that it should be much easier to see how much was dosed per day, when looking at the history.

And a question about your idea - why tell the dosers to dose so much more slowly than they can? Unless there's a reason not to, I'd just as soon have the pumps run at max speed, which would be whichever the slower rate is of the two pumps.

 

[Gaël]

Hello,

It's a software limitation, we have to modify parts of the code to change that, it's not planned at the moment, it's not something that has been requested so far. You can make your request at [email protected]

Gaël

 

[KenO]

Thanks Ken. Yes, I'm totally with you. I know how to do what you're saying. When you started talking about calibration and being smarter, I thought you were going to say to tell the doser that the max speed dosing rate was much much less than it actually is - so tell it that it's 1/10 what the true calibrated dosing output was, and then when you tell it to dose 3000 ml, it would actually dose 30,000 ml. But that wasn't what you said. But maybe that would work too!

Anyway, I like your idea. I would still like to know if it's ill advised to dose that much all at once. My suspicion is that there is not a good reason for the max of the doser to be 3 liters per dose. But I don't want to assume that, maybe there is a good reason for it, like it could damage the pumps if you tried to dose more than 3L at a time. I'm still hoping Gael will weigh in.

I wonder what the dosing history would say, if you did it your way? An advantage of dosing all at once is that it should be much easier to see how much was dosed per day, when looking at the history.

And a question about your idea - why tell the dosers to dose so much more slowly than they can? Unless there's a reason not to, I'd just as soon have the pumps run at max speed, which would be whichever the slower rate is of the two pumps.

like you said you can go as fast as the software allows you to go. The 150ml/min was just to toss some numbers out there. When I was testing the Maxi 2.2 I was doing 43.2L/day on a continuous flow. 30ml/min x 60min x 24 hours. I could do it in a shorter time frame, but it works. I didn't have the record turned on when I was testing. I don't remember if the continuous turns that feature off, I think it did. There is a max number when setting up the highest level and yes you would have to go with the speed of the slowest pump. Give it a try and report back.

 

[Dave-T]

Hello,

It's a software limitation, we have to modify parts of the code to change that, it's not planned at the moment, it's not something that has been requested so far. You can make your request at [email protected]

Gaël

Ok, thanks. So it's somewhat of an arbitrary number. Seems like it would be an easy fix and I'd put In the request, but if nobody else has asked for it I guess I won't bother. I wouldn't assume that nobody would make use of the ability to dose over 3L, just because nobody has asked for it. Few people go to the trouble to make such requests.

Anyway, I think I misunderstand something. Either that, or I found a bug. I just calibrated one of my pumps at max speed. I ran calibration runs 4 times and measured what was dosed. I got 309, 302, 308, and 307 ml dosed, so an average of 306.5. I entered 306.5 in the "Max Flow" field for the pump, and put 282 in for the desired flow, and saved the settings. I then told the pump to dose 282 ml. But, it then dosed 307 ml instead. Can you explain that? Shouldn't it have dosed 282 ml when I told it to dose 282 ml?

 

[Gaël]

Ok, thanks. So it's somewhat of an arbitrary number. Seems like it would be an easy fix and I'd put In the request, but if nobody else has asked for it I guess I won't bother. I wouldn't assume that nobody would make use of the ability to dose over 3L, just because nobody has asked for it. Few people go to the trouble to make such requests.

Anyway, I think I misunderstand something. Either that, or I found a bug. I just calibrated one of my pumps at max speed. I ran calibration runs 4 times and measured what was dosed. I got 309, 302, 308, and 307 ml dosed, so an average of 306.5. I entered 306.5 in the "Max Flow" field for the pump, and put 282 in for the desired flow, and saved the settings. I then told the pump to dose 282 ml. But, it then dosed 307 ml instead. Can you explain that? Shouldn't it have dosed 282 ml when I told it to dose 282 ml?

Unfortunately, it is never as simple as we might think. Variables and resources in the code are calculated and defined just right, it is not a simple arbitrary limit and we will probably have to change the variable type and review different parts of the code to change this.

For the volume issue when using the desired flow, yes we are already aware of that. Sorry. Will be fixed ASAP.

Gaël

 

[KenO]

Ok, thanks. So it's somewhat of an arbitrary number. Seems like it would be an easy fix and I'd put In the request, but if nobody else has asked for it I guess I won't bother. I wouldn't assume that nobody would make use of the ability to dose over 3L, just because nobody has asked for it. Few people go to the trouble to make such requests.

Anyway, I think I misunderstand something. Either that, or I found a bug. I just calibrated one of my pumps at max speed. I ran calibration runs 4 times and measured what was dosed. I got 309, 302, 308, and 307 ml dosed, so an average of 306.5. I entered 306.5 in the "Max Flow" field for the pump, and put 282 in for the desired flow, and saved the settings. I then told the pump to dose 282 ml. But, it then dosed 307 ml instead. Can you explain that? Shouldn't it have dosed 282 ml when I told it to dose 282 ml?

I see there will be a fix coming for this. I saw the same thing. I thought I did something wrong so I did a second set of my 5 calibration method. Doing it again and entering the new number fixed the issue. Might be a work around until the fix comes out.