ATO with doser questions

[sylvius]

I have a 75 gallon display in a basement, so fairly cool surroundings but a little higher relative humidity. I think ATO is currently less than 1 gal/day but haven’t been monitoring that closely as osmolator keeps things topped off and I have a large RODI reservoir on which I push a button every few days to auto-refill. I’d like to switch from tunze ATO to doser for a couple of reasons:
1) To facilitate sending some of the ATO water through a kalk stirrer. This is the primary motivation.
2) To be able to monitor and learn more about losses so I know how long the reservoir will last, etc.
3) To make it easier to pause ATO for various tasks. I know I could do this by putting the osmolator on a switched outlet, but every time it is power cycled it runs for about 15 seconds.

Now for the questions:
1) Can doser 2 manage ATO of up to about 1 gpd without too much stress on the motor?
2) Searching I have found a few different ways people have tried to control send ATO through kalk or not (I don’t have KHD at this point) but is there a preferred way? I was thinking of just trying to find a max volume of kalk each day and when that is exhausted falling back on straight RODI.
3) The return chamber of my sump is not so large (12.5x5 inches). Is a single float valve sufficient to run the ATO (with probably a second high water float as an emergency backup)? Would you put a delay on it to prevent it running very often or is frequent small dosing desired? I just don’t want to burn the motors.
4) Are optical sensors significantly better for this purpose than floats? I already have the floats but could add optical if really necessary.
5) Only tangentially related, can a float valve live submerged as a low water alarm that shuts down the return and, if so, does that significantly shorten its lifespan?

Sorry for all the questions (and I am sure there will be more as I try to implement other tank tasks). I am trying to search through what’s already available.

 

[Lasse]

1) Can doser 2 manage ATO of up to about 1 gpd without too much stress on the motor?

I use a doser 2 for ATO in my system for about 3 months - daily amount around 4 L (1 G) Its not the total amount that´s of interest - is the longest time the motor will run that is most critical - not longer than 15 minutes and after that 15 minutes stop. However I have a diy dose pump with higher flow at the moment.

2) Searching I have found a few different ways people have tried to control send ATO through kalk or not (I don’t have KHD at this point) but is there a preferred way? I was thinking of just trying to find a max volume of kalk each day and when that is exhausted falling back on straight RODI.

Never done it but it is possible - however there is a need of two pumps IMO

3) The return chamber of my sump is not so large (12.5x5 inches). Is a single float valve sufficient to run the ATO (with probably a second high water float as an emergency backup)? Would you put a delay on it to prevent it running very often or is frequent small dosing desired? I just don’t want to burn the motors.

My return chamber have around 10 - 15 L in it. I use one single float valve that run the doser as soon it is needed. Its a variation of around 0.3 - 0.5 L Have a delay of 5 sec because I do not want a wave effect. It has also a max time

4) Are optical sensors significantly better for this purpose than floats? I already have the floats but could add optical if really necessary.

I do not know - have always use floats

5) Only tangentially related, can a float valve live submerged as a low water alarm that shuts down the return and, if so, does that significantly shorten its lifespan?

Yes - I do not think so

Sincerely Lasse

 

[Vinny@GHLUSA Verified Sponsor]

If you wanted to run an ATO function with only one sensor, that is perfectly doable. When you use a GHL sensor, you get to benefit from the built-in failsafe which forces the task to shut down in case a safety time limit is reached.

@Lasse pretty much covered the rest of the questions.

 

[sylvius]

That's perfect, thank you both! Can I program a 15 min max run time with 15 min minimum recovery after run or does doser enforce the duty cycle automatically? If I do kalk and non-kalk for sure was anticipating needing a second pump for that.

 

[Lasse]

Here is my ATO configuration. With doser 2 - you may need to rise the maximum on time a little (red). If the surface in your return chamber is very "wavy" - you may use a higher delay time (blue)

Sincerely Lasse

 

[sylvius]

Awesome, thanks, that’ll speed things up for me.

 

[sylvius]

Quick clarification on the failsafe time limit. Is it correct that if it hits the time limit it will never run again until after the sensor cycles? Said another way, if the sensor gets stuck and doesn't stop the pump by the time limit, it will not run again until the sensor goes on then off again? Will it alarm on time limit reached?

 

[Lasse]

Quick clarification on the failsafe time limit. Is it correct that if it hits the time limit it will never run again until after the sensor cycles? Said another way, if the sensor gets stuck and doesn't stop the pump by the time limit, it will not run again until the sensor goes on then off again? Will it alarm on time limit reached?

Correct - it will not work before it will be resetted. You can chose if you want a automatic reset or ig you must do it manually.

Sincerely Lasse

 

[Ditto]

Quick clarification on the failsafe time limit. Is it correct that if it hits the time limit it will never run again until after the sensor cycles? Said another way, if the sensor gets stuck and doesn't stop the pump by the time limit, it will not run again until the sensor goes on then off again? Will it alarm on time limit reached?

Once the time limit is reached the ATO will remain off until you reset the level (sensor) and will alarm the P4 blinking in Red and will also send a notification/alarm if set up.

 

[sylvius]

Thanks so much @Ditto @Lasse and @Vinny@GHLUSA ! I got it all set last night and it was working this morning. Seems like it's running every 15-20 minutes for 45-100 seconds, which is cool from a tank stability perspective and especially when I start running kalk through it (I need to re-find the thread about running kalk or pure water based on pH).

As far as doser wear is concerned, am I better off with a longer sensor delay so it runs longer but less often or is the only thing that matters total daily runtime (so long as never longer than 15 min per run)?

 

[Dr. Jim]

FWIW, I set the delay for 10 sec for my 40 gal system and that seems to work nicely. Originally, I set it at 40 sec but that seemed to be too long because after the water level reached it's "original level" the pump continued to run for another 40 seconds which pumped in too much water.
IMO, it is better to have a delay to reduce the number of times the pump comes on for concern of "wear and tear."

 

[Lasse]

FWIW, I set the delay for 10 sec for my 40 gal system and that seems to work nicely. Originally, I set it at 40 sec but that seemed to be too long because after the water level reached it's "original level" the pump continued to run for another 40 seconds which pumped in too much water.
IMO, it is better to have a delay to reduce the number of times the pump comes on for concern of "wear and tear."

The delay in the sensor part is only to prevent waves from turning it on and off rapidly. It requires the signal to be steady. I usually use 1 - 3 sec

Sincerely Lasse

 

[Dr. Jim]

The delay in the sensor part is only to prevent waves from turning it on and off rapidly. It requires the signal to be steady. I usually use 1 - 3 sec

Sincerely Lasse

Right.....so if it is set on 10 seconds, the pump won't turn on and off as frequently as it would if set on 1 sec, correct? (That was the point I was trying to make).

And..... what is that on your head in your new photo??

 

[sylvius]

I thought the delay time will also delay it shutting off by the same duration so a longer delay should equal longer runtime, no?

 

[Dr. Jim]

I thought the delay time will also delay it shutting off by the same duration so a longer delay should equal longer runtime, no?

That’s what I think (and said in my first post). So it will run longer but there will be fewer on and off cycles (which might reduce the “wear and tear.”)

 

[Lasse]

That’s what I think (and said in my first post). So it will run longer but there will be fewer on and off cycles (which might reduce the “wear and tear.”)

No it will not run longer but because the fill rate is higher that the "water loss" rate - it will overfill a little, hence give a little lesser filling cycles

Sincerely Lasse