Osmolator on a Neptune controller

[johns]

Roger-

Do you know how the osmolator functions when used in conjunction with a controller?

I just got a Neptune Aquacontroller Jr. and want it to turn the osmolator on only at night-time (for overnight kalk water top-off). To prevent the kalk from all being added at once, I was going to give some commands for pH limits.

For instance, if my pH at the end of the day is 8.0 and I begin my kalk addition, I could tell the osmolator to shut off the top-off everytime the pH hits 8.2 (just an example). So the osmolator might come on for a minute or so, the pH will spike, then it'll shut off to wait for the pH to come back down a bit. Then the cycle should repeat over and over again.

My question is this - with the osmolator plugged into the Aquacontroller and being commanded to add top-off according to pH, is the level sense that shuts off the pump still functional? In other words, even if the pH is below the stopping point (8.2), if the water in the sump is at the height of the osmolator's level sense indicator, will the pump shut off preventing a flood?

 

[rvitko]

I don't know. I don't think this is necessary since the amount the osmolator dispenses is so nominal it should not lead to any spike in pH if run continuously. If I were to try this I would design a circuit board that a relay is switched to run one pump connected to a kalkwasser dispenser at night and during the day another pump running just freshwater is run. I do think those this would be gadgetry for no other sake then to have gadgets. Not that I am above that but I think in this case it is too complicated and may fail catastrophically should the pH spike from a large sudden dose. Not to mention by turning off the Osmolator you reset it's safeties so you could have flooding since this would bypass the 10 minute countdown everytime it turned off and on.

 

[johns]

I will try to explain my reasons for wondering this. But I think you hit upon it. It is in order to do the top-off only at night to alleviate a large overnight pH swing.

The reason I wouldn't want to add freshwater during the day via another pump is to maximize the amount of limewater I add at night (I would like limewater to be my only source for Ca and Alk in a SPS-heavy tank, but dont know yet if I could keep up with kalk alone).

So I would like to add as much volume as possible (the maximum is, of course, my evaporation amount) for added Ca/Alk. But I would like to try to add it all overnight, to aid in pH stability. Since I just got a Neptune, I was trying to figure out if this would work in conjunction with that.

What I was thinking was, I would start the osmolator after lights out, have it add limewater for a minute or so at a time, and shut off every time the pH spikes slightly. Then wait for the pH to go back down before adding again. In addition, there could be a time limit involved - like every time the osmolator shuts off due to the pH spike, it must wait 10 or 15 minutes before it can turn back on again. Of course, pH would also have to be back down again in that time, or the osmolator could not start again.

My only concern is as I said, i am not sure if the osmolator's own level sense can shut the pump off. Otherwise the Aquacontroller might keep trying to turn the osmolator on to compensate for low pH and could raise the water level too high or flood the sump.

Anyone try anything like this? Cant be that novel of an idea?

 

[blgreef]

Just a thought, may be easier to get a peri pump and a float switch to set a high water mark, get the aquacontroler to drive the peri pump based on PH and time of day, and also have it kill the pump if the float switch closes.

Leave the osmo unit just as a final water level control.

The benefits are:

With a peri pump you can set the exact amount of water added and it will survive the KALK as only the tubing will be in contact, the high water level switch kills the peri pump and prevents a flood and having the tunze left on stops any low water etc


I ran the osmo with two pumps one for fresh and one fro KAlk using a sep control to switch based on time of day, but find it better to have a dedicated feed for the Kalk drip it slowly and use the tunze for what is was designed for, better to keep the two systems seperate.

 

[johns]

Thanks. There probably are ways to do this by adding a second pump. I was trying to see if I could do it without any more pumps though.

If it's going to take another pump, I'm probably going to resign to just leave things alone - not control the osmolator with the Neptune - and live with the pH swing.

But I might try this first unless anyone knows for sure it cant work.

 

[johns]

For those of you interested, I did try controlling the osmolator in the way I mentioned above and it does appear to work. Now I only did this for a short time, but what I did was plug the osmolator directly into a DC8, and enterred a command for the osmolator pump to run any time the pH of the tank got below 8.25. I took the osmolator level sense control out of the water to simulate that the sump water level had fallen. The pH when I entered the command was pH 8.23, so the pump immediately turned on and started dosing kalk. After about a minute of dosing the pH spiked up above 8.25 and the pump cut off. I replaced the osmolator level sense control back into place in the water, and of course the water level was just slighly high now. I then tried the opposite scenario - I changed the command for the osmolator to run if the tank got below pH 8.4. However, the pump would not run, presumably because the osmolator could sense that the sump was at the fill level. As a double-check, I took the level sense control out of the water again to simulate that the sump water level had fallen and the pump immediately turned on.

I guess I still dont see a really great way to control the sump water volume by way of pH, but I thought I'd just see if the commands would work first. And also make sure that the osmolator shut off switch would still work.