Calcium Reactors/Ph settings for controller

[Toiler]

I have a calcium reactor/CO2 tank; to control it all I have a Pinpoint PH monitor/controller.

After calibrating the monitor where should I place the PH probe? Ideally I'd like to place it in the sump either before or after the calcium reactor.

What PH level should I set the controller to turn off the reactor? My LFS said I should have it turn off at 8.1 PH, does that sound correct?

Does PH in the tank rise naturally?

 

[Anonymous]

There are two ways to use it, and let me outline both and you decide the rest.

1, using the pH controller to maintain optimal pH for the ca rxtor so that it runs optimally.

2, using the pH controller to make sure the pH of the tank is never below certain value.

A, placement of the pH probe.
In case 1, you put it in a small container that the reactor drain directly into, or inline with the output of the reactor. A few (most don't) rxtor have a access hole for the pH probe.

In case 2, you just put it somewhere in the sump or the display tank. Basically anywhere that reflect the average sampling of the tank.

B, pH setting of the controller.
In case 1, you want a pH of ~6.5, a value that many considered to be the optimal pH to run a rxtor at.

In case 2, you want to set the pH ~8.3 or slight below, so 8.1 is not that much off.

pH of the water will be depressed slight by running the reactor, and once the controller turns off the CO2, it will come back up slowly. As long as you drip the output of the reactor in a high flow area, and with good air exchange (skimmer), pH is rerely an issue with the use of rxtor.

 

[jdieck]

I assume you want to use the controller to maintain the PH of the reactor's effluent. In that case as LOULE suggested you can hang a little cup on the side of the sump where it can overflow into it and place the controller's PH probe in the cup submerget at least 1 to 11/2" in the cup's content (Reactor effluent). As Loule suggest a good initial setpoint is a PH of 6.5 but as the controller operates within a minimum of 0.2 range and cuts of the solenoid at the middle of the range you will need to set up your max at 6.6 and your min at 6.4 with your range at the 0.2 minimum between max and min.
Try to have the controller not to switch off and on too frequently ao try to adjust your CO2 bubble rate so the PH drops from the max to the cut off in the logest time possible. Ideally you want to set the bubble rate such as the PH stays constant without the controller having to operate.

During the setup period watch out and test your alkalinity frequently as 6.5 PH may be too low for certain easy to disolve medias like ARM and may increase your alkalinity too fast in which case you need to increase the PH set point and / or lower your effluent rate.