View Full Version : general questions

08/13/2008, 08:26 AM
Thinking of building a controller into my setup and have a couple of questions:

Is the primary difference between the ACjr and the AC3 that the 3 has inputs for 2 ph monitors ? If so, would you monitor the ph in your main tank (or sump) and inside the calcium reactor ? Any "control" functions on ph would be based on the ph reading on the tank, correct ? Why would you want to monitor ph in your reactor ? Would it just be to be sure that your reactor is functioning to it's fullest potential ? ie media is good, correct co2 saturation, etc. ?

If you go with the jr, then you would want to put your probe in your tank or sump, correct ? the main tank would be your primary or end concern and if that got out of whack then you could manually check your reactor with a test kit ?

Next, can either of the units use float switches as inputs and controls for the DC8 outlets ? I'm trying to fashion an auto water change system where I want to control pumps with float switches and time (turning on a pump once a week for a specified length of time for water out and a float switch to pump water in). Can this be run through either of these units ?



08/13/2008, 11:02 AM
When using a reactor, you want to measure the effluent of the reactor. It should be coming out at 6.5, that’s the saturation point at which the CO2 dissolves the media. You use the effluent reading to control the solenoid on the CO2 regulator.

If you go with the jr and use a reactor you want the probe to measure the effluent.

The jr allows for one switch and the III allows for 2 switches. You can use a break out box for more switches.

08/13/2008, 01:23 PM
I just want to make sure I'm understanding. If you use the Jr, then you want the probe in the reactor and use that measurement to control how much co2 is dissolved. That's your "primary" measurement and control on PH.

If you have the AC3, the second is placed in the sump to measure the tanks PH. Then this could control how much effluent is being added to the tank to achieve the desired PH. This second probe also provides "real time" readings on tank PH, thus saving having to do a manual test. Does that sound right ?

thanks for the help

tank control systems and calcium reactors are new to me.

08/13/2008, 02:46 PM
you don't "control" tank PH; it is far more complex than just controlling C02 and CA, Kalk, etc. If you wanted to, and you don't need to, control a Ca reactor then you would use a PH probe to control the PH within the reactor (e.g., a probe mounted internally to the reactor or by measuring output effluent using a cup/overflow method). PH probe in tank water is more about monitoring than it is control. A Jr supports 1 PH probe, you can monitor tank OR reactor, an AC3 can do both (but you loose the ability to monitor ORP unless you get an PX1000).

There is a comparison of the different controllers here:


08/13/2008, 03:54 PM
but let me ask a different question then . . .

are the capabilities of the JR (one probe) best used in the reactor and controlling CO2 and effluent PH ?

what would the the second PH probe and "control" functions best be used for ?

Sorry if I'm sounding dumb . . .

Just considering buying a controller and want to put my money to it's best use and also get the most out of the equipment I decide on.


08/13/2008, 08:10 PM
It all depends on what your setup it. These are questions one has to answer themselves depending on their equipment, money and overall goal of their tank. With the information you have given us we don't know if your are a fish only, sps, lps, or leather or some combination of above. This is what I mean by you sort of have to answer this yourself.

Myself I wanted the ability to use the built in web server to monitor the tank remotely so I chose the ACIII and yes you can do that with a Junior but I like the ethernet connection. Just my preference. does it make it the best? Who knows.

08/13/2008, 10:10 PM
nevermind . . .

I don't seem to be communicating my question