Calcium Reactor Help - Monitoring Effluent pH

[AV8er]

So I am setting up my calcium reactor and have a pH controller to regulate the solenoid. However, it seems to me that there are 2 pH measurements that need to be considered. One would be the effluent pH and the other would be the tank's pH.

I understand that the effluent pH needs to be monitored to ensure that the pH in the reactor remains within a stable range, but isn't the tank pH the "more important" measurement?

That is, if you only have a pH controller on the effluent, even if the effluent pH remains around 6.5, outside factors could continue to depress the actual tank's pH (e.g., excess CO2 in the home, etc...), and the regulator won't close the solenoid, compounding the problem.

I guess this is a long way of asking which pH measurement is more important for regulating the reactor solenoid.

 

[delta]

Tune your calcium reactor then figure out how you deal with the low PH effluent entering the tank. So worry about that PH of the effluent in the reactor to dial in you reactor

I run my effluent into my protein skimmer to blow off any excess CO2 my effluent has zero effect on tank PH, my tanks run a high PH.

you can also add a second chamber to the reactor to absorb more CO2 before it hit the tank.

 

[MikeG]

+1, I would do as Greg mentioned. Duial in the reactor and then look at other options to bring up the tanks pH if needed.

 

[AV8er]

Okay, I'm with you guys... make sure the reactor pH is well regulated and tuned-in, and worry about the tank pH if/when it becomes an issue.

So then let me ask you this - I have a second reactor chamber that I was going to use to, as you said, help absorb the extra CO2 from the main reactor chamber, but I don't have a pH probe port that would allow me to measure the pH in the main reactor chamber. So I'll be measuring the effluent as it exits the second reactor chamber. Do I need to worry about compensating for the pH increase between the two chambers? Since the effluent pH exiting chamber #2 is higher than the pH in the main chamber, do I need to worry about setting the pH controller at some point above 6.5 to prevent the pH in the main reactor chamber from going too low and nuking all the media?

Thanks fellas,
Jon

 

[JohnK]

You can guesstimate on compensating. If you're going for 6.8 in the main body of the reactor, then shoot for 6.9 or 7 coming out of the second chamber and let the reactor run a bit and see how it's working (you can test the effluent for alk, as long as it is elevated well above normal you know the reactor is dissolving the media to some extent. If after a couple of weeks the reactor isn't keeping Ca and alk where you want them, then you can increase the effluent rate and or lower the PH a bit.)

The other option is to install a probe holder in the main chamber of the reactor which is pretty easy on most designs. Simply drill and tap a hole in the lid (or install the appropriate parts modded into the existing recirculation plumbing) and install a compression fitting or modified john guest fitting, and then the probe slips right in and doesn't leak. Generally you can do this in either the lid of the chamber, or somewhere on the plumbing. LMK if this doesn't make sense, I can post a pic..