Upgrade Ca Reactor?

[ari5736]

I have a GEO 612 on my 125 gallon that is moderately stocked with hard corals (i.e. a few soft ball size colonies) and a 6" maxima clam. I have a full stream coming out of my reactor and the reactor was automatically controlled to turn on at 6.7 and turn off at 6.5.

I was having a hard time keeping the kh of the tank 8 even with kalk additions in top-off. I lowered the ph to turn on at 6.6 and off at 6.4 and topped of the media with the hope that this keeps the kh steady at 8.

So my first question. I know that a CA reactor is just supposed to keep the kh stable and that additions should be made with kalk or 2 part etc...
I find raising with kalk to be very difficult because it takes along time through dosing and ph considerations, so is there a faster way to safely raise kh to around 10.

Second question, if I still have a hard time keeping the kh steady with reduction in ph in reactor, do I need a bigger calcium reactor, more flow through the present reactor, lower ph again? Thanks.

 

[Boomer]

Well, first ari, people often forget about this. Just because you have a low pH at the effluent does not mean more dKh /say. You also have to look at flow. If the flow is to fast not much media will dissolve and you also may end up with a lower output pH as there is not enough time for the reaction to actually dissolve the media. Have you tried to slow down the flow rate ? You may find that the Alk will go up to high and have to raise that pH. It is also some what helpful at times to let the effluent drain into another container with media to help that pH issue and remove some of that CO2 keeping that pH lower.