I'll likely be the contrary voice here... but I wouldn't overanalyze your water parameters. I've kept frogspawn for 15 years... under PC, halide, and LED lighting, and in my experience, they don't like a tank that's too perfect: Not too 'clean' (they like organics in the water column)... no too much light (they're easily scorched)... not too much flow (their interior skeleton is a series of really sharp ridges that will cut up the fleshy parts with an amount of flow that's fine for torches, grape, etc. like a series of knives, cutting their way from the inside out. Even the boss at my LFS, a really quality operation with 40+ years of experience, recently almost killed one of the frags I gave them by putting it in their display tank with flow sufficient for SPS. Whereas the heads in his low-flow 'for sale' tank were doing just fine.) Frogspawn also seem to really appreciate having an active refugium as part of your system. If you're in the greater Los Angeles area (I live in the San Fernando Valley) I'd be glad to spot you a couple of heads of purple tip frogspawn... plus one of my really nifty orange-tipped frogspawn, as long as you're willing to drive. I haven't got any ability to ship. Hope this helps...
Chuck