K.I.S.S.

That's it. I'm done branching off and trying new things, making my (and my fishes' life) harder than necessary. I'm going to disregard my concern for the water hardness and begin relatively strict EI dosing on my 30 and 10 gallon tanks; at least, the TDS will be kept below 400 ppm, because high nitrates is the only reason I can think of that my fish would be getting sick. On that note, I did a water change on the 5-gallon too, which will get less frequent water changes, but I wanted to get the TDS down safely below 400 ppm.

There are a lot of things contributing to this. Compounding my rash of sick fish in the 30-gallon, the harlequin went missing in the 5-gallon (not even a body to pull out), and I thought I had killed off my tiger shrimp with all of the fish medication. Well, I might have killed off a couple, but I saw at least one today (though he looked kind of opaque). The big water change was necessary to reset the water -- at this point, I'm hoping the cory has gotten whatever medication he needs. From here on out, he's on his own. No more medication, but plenty of clean water.

Cool stuff to report for the 10-gallon, though. I saw a pregnant RCS -- I'm hoping the eggs are fertilized and will become my first shrimp spawn! And yes, I know I need to get rid of that distracting background.