Whats your kh drop daily ? Might not need it
Start at 7 and change the ph. Water flow should be a min drip 1 or 2 seconds.
+1
The more CO2, the lower the ph. Or the lower the flow through the reactor (so the media has more time to dissolve,) the lower the ph. But like chadfarmer said, you do not want too slow of a flow or else the effluent line (the line from the reactor to the tank) has a tendency to clog. You'll need to get your drip rate to 1-2 drops per second, then adjust the bubble count to get the ph in the reactor down to 7.0. Once you are dialed in (7.0ph, 1-2 dps), give it a day or so and see if it is keeping up with your tanks demand. If it isn't, you can either lower the ph in the reactor (up the bubble count) a little or increase your feed rate ( which, will also include upping your bubble count to keep it at 7.0) to increase the amount of alk the reactor supplies to the tank.
Be careful when you drop the ph in the reactor. All brands of reactor media will turn to mush and be ruined if the ph gets too low. Different brands have different "melt points". Go slow.
Also buffer to your recommended levels and reactor is used to keep it there
This is an important point not to forget. The reactor should be used to maintain alkalinity, not to try to raise it. Use 2-part to get it where initially want, and back to where you want it until you get it "dialed in" and it is maintaining the kh on its own. As your tanks demands for kh increase, you will need to adjust the reactor accordingly, or supplement the kh with kalk.
Also, any and all changes should be slowly. Over the course of days. Once you have the 1-2 dps and 7.0ph, leave it for a day and check it in 24 hours to be sure it is still the same. It may take some time for the reactor to equalize. If your needs are not being met, adjust and wait 24 hrs to see if it is enough. (If your kh is the same as it was 24 hours before you made the changes to the reactor, then it is dialed in).
Hope I didn't confuse any more than you already were.
