In my experience a feed pump is necessary. A reactor can easily lose suction without it and will then no longer work until the situation is corrected. A little pressure also makes it easier to maintain a steady flow rate.

A pH probe port can be purchased from Home Depot or most other hardware stores. The hard part is then finding a large tap to thread a hole for the fitting... https://www.homedepot.ca/en/home/p.f...000124751.html

Aquatic essential calcium reactor how to?
 

Oh perfect! That makes my life easier. For a feed pump I was going to make a manifold off a seperste DC pun for some reactors. Wold tapping off that cause any issues or do the trick for a feed pump. In Theory it can only take in what it drips out to make space for

Now I need to find a PM1 module to run an extra probe.

Does it matter if the unit sits inside the sump? Likely depends on the pump Not sure if it will fit otherwise as of yet. So it looks like I need a 1/2" tap for that fitting?

The pump is also a little loud. Would a Jabeo DC pump work well for this?

The manifold idea sounds good. I feed my skimmer, CA reactor and media reactor with the same pump. Inside the sump is probably best. Things often leak sooner or later. Ask around locally to see if you can borrow a tap. I bought one and it was $30-40... I don't have any experience with the Jabeo.

I ordered a 1/2" tap of Amazon last night.! Perfect. I also have 1/8 and 1/4 from a set I bought a while back. Picked up some manifold parts too! I love building stuff!

Also found a used ehiem pump that should work and be fairly quiet. I'll give it a test and buy it if it's silent :)

http://uploads.tapatalk-cdn.com/2016...24e5d3122d.jpg

What drip rate for effluent and bubble count for co2 is a good starting point with this reactor?

I like to keep the internal pH around 6.6, let your pH monitor or controller determine how much gas is needed to achieve that. How much flow you need through the reactor depends on the calcium carbonate demand of the tank. Start slow (probably just a slow drip), keep testing and adjusting Alkalinity and Calcium, and gradually turn up the flow until the output matches the consumption.

To expand a bit on what he said:

From what I have read you want the PH inside your reactor to sit between 6.5 and 6.7 in order to dissolve your media. Below 6.5 is too fast and turns the media to mush? above 6.7 and you aren't doing much. So you have two ways to control what your ph is, CO2 bubble rate(gas amount) and effluent rate. High gas rate plus high effluent rate equals more alk and calcium. Low gas rate and low effluent rate equals less alk etc. It is about hitting your PH target while finding the demand of your tank. So you adjust either in whatever combination to get where you want to be.

Because I have a low demands at the moment my gas shuts off in the evening for several hours also. On my setup the gas release amount will only go so low, luckily I have an electronic regulator so it can be controlled by a timer.