Litermeter III - can main pump and optional extra 2 pumps be controlled independently

[capman]

Looks like I'm getting a Litermeter III for topoff. twopartsolution.com has these for what appears to be a very good price.

I'm wondering though...

Is there independent shutoff control for the main pump and two optional external pumps, or are they all shut down simultaneously (e.g. if using a water level switch)?

I'd like to use this setup for kalk topoff as well as for two-part dosing. Ideally, it seems that it would be nice to be able to put the two external pumps on a timer (to give constant dosing of two-part) and have the main pump controlled by a level switch (for topoff with kalk).

My guess though is that a topoff level switch will turn off all three pump heads at once. I guess this is not so bad really...if we assume that evaporation is more or less constant, then the pump will run a fairly predictable amount of time each day, and the amount of two-part going in can be adjusted (within the context of a certain evaporation rate) by adjusting the flow rates of those two pumps.

Am I understanding this all correctly?


ALSO...can anyone tell me what the maximum number of gallons is that this can pump per day? I need this pump to finish off our animal room system (that has lots of surface area for evaporation in its multiple tanks), and I need to make sure it will pump enough to keep up with evaporation. My guess is it will be fine, but I figure I'd better check before buying, and the sales web sites don't seem to tell (or I'm simply missing it).

[David Grigor]

Bill, I have a LMIII with 2 remote pumps and the top off control.

It depends on where you put the top off control. If you plug the top off control in attemp to control pump A ( the built in one ) then yes it turnes off the whole unit.

But.... you can put the top off control between pumps b or c and it will be independant.

Thats how I have it 2 part I use pumps a & b, Pump C is for Kalkwasswer and use the top off control on that one so it will not dispense when water level is reached. Top off control module has no effect on pumps A & B.


The max I believe it is 99 liters which should be about 25 gallons a day.

[capman]

How do you control the rate of 2-part dosing? Do pumps A and B just run continuously at a low pumping rate?

Thanks.

[capman]

And the 25 gallons per day is per pump head? Is this correct?

[Redwinger]

How do you control the rate of 2-part dosing? Do pumps A and B just run continuously at a low pumping rate?

Thanks.


You can program each pump individually. It will then dose the amount evenly over a 24 hour period.
And the 25 gallons per day is per pump head? Is this correct?


Per pump

[David Grigor]

It doesn't dose continously. The pumps themselves are only one speed. The microchip dispenses 150 times a day ( I think every 3 minutes ). So they are more like bursts. It does have eprom memory. So you can turn it off and not worry about loosing the calibration or ml per day settings. I actually have mine only run 12 hours a day by putting the LMIII on a seperate timer. So I'm only dosing the 2 part and Kalkwasser at night.

[capman]

You can program each pump individually. It will then dose the amount evenly over a 24 hour period.

Do you mean you can have some of the pumps running at different times than the others (for example, some pumps only run between 9:00 and 10:00 in the morning, while another pump only runs at night?)? Or, can you just set the rate that each pump dispenses fluid?

I guess my detailed questions are sort of moot at this point though, since I've decided to take the plunge and get one, and figuring out precisely what it can and can't do might be pretty straightforward once I have it in my hands. Looks like I'll get the 2 extra pumps and the level switch as well.

Thanks everyone for your help.

[Redwinger]

Nope if you set it to 25ml a day it will just dose the 25ml over a 24 hour period. As david says it will be intervals of short bursts.

[David Grigor]

Bill, Each go on/off 150 times a day ( every 3 minutes ) but no two pumps are on at the same time. Well, I have never tested it enough to know if you programmed 99liters it may in fact stay on the whole time.

So you don't have to worry about the ALK and CA portions going off at the exact same time. Should be at least a minute apart give or take.

Good question though.

[capman]

So what this means is that if you put things on a timer (or perhaps have it controlled by a pH controller that shuts it off if the pH goes too high) it is an all or nothing thing.... all pumps running at their 3 min intervals or no pumps operating for the duration.

Being able to control one (or more) pump separately via a level switch is a really nice feature though. This would allow predictable dosing of the 2 part while not overflowing the pump with kalk topoff.

I think I am going to like this pump! (for the cost, I guess I'd better!).

[David Grigor]

Using a controller I'm sure you can rig up something just like the top off module with any type of relay switch if you wanted to but you are correct. Nothing out of the box from Spectrapure will turn off pump based on PH.

Yes if can be done with a 12v relay though ( For pumps B & C only, not the built in pump ). About $10 in parts.

[capman]

I think what I'll do is have one pump controlled by the water level switch for kalk dosing/topoff, and as a safety measure, I'll have the whole thing controlled by the AquaController, which will turn off all dosing if the pH goes too high.

[David Grigor]

If you turn off the whole thing, then nothing required you will obviously just plug the LM3 into the controller.

I'm doing the same thing now, but set just as a timer on the controller but PH is not bad safety measure to if you okay with adjusting the 2 part periodically if PH outages occur.

[capman]

Seeing as a high pH accident caused my disaster in the 220 a few years ago, I think the high pH cutoff is a good idea. Admittedly, this disaster was made possible in part by some bad system design that I will not repeat, but I don't want pH of a tank going to 9.2 or 9.5 (I forget now what it was exactly) again by accident if I can help it.