What is your targeted effluent drip rate or cc/min ? (video will help) Ideally go for fast drip (instead of slow drip).
What is your current pH of your calcium reactor? What is the lowest pH it'll hit?
Is the Maxijet a dedicated pump for the CR or T off for other purposes as well?
You can attempt to clean your effluent tube. It may be clogged with fine bits of melted CR media that has become mush. Looks like this...and may get clogged in the effluent tubes.
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What kind of valve are you using for the effluent tube? Ball valve? Needle valve or Pinch valve (see pic below)
IMO, a pinch valve is best for CR effluent as there are no sharp corners internally. It may still clog if its filled with mush but does reduce the chances. I try to illustrate below.