PPM Meter is plenty fine for reading nutrient strengths. Not sure what nutrients you are using but I'd recommend getting something like General Hydroponics Flora *ova (site is censoring the word, begins with an N) Grow and Bloom, they are very simple to use. I'd also recommend a bottle of Advanced Nutrients pH Down. It is a stronger pH down than GH's version, meaning you'd need less and the bottle would last longer. Those are the things I'd do to get the plant health back on track.

Thanks! The house was empty for a year and a half before we bought it. There's a 30 yr old Camillia bush in the backyard that is HUGE, a well pruned japanese maple, a high producing satsuma tree, and as i discovered this past winter, a TON of daffodils randomly placed all over. (My mom says I should dig them up and give them a structured layout so they can avoid the lawnmower). Also Spider lillies and rose bushes that flower beautifully are hidden all over. And my favorite is the double-bloom hibiscus tree. I have wonderful honey bees everywhere and it seems the previous owner was quite the gardener. It has been such a joy to discover all these gorgeous colorful presents around my yard.

Sorry for the loss (assuming the rest browns out). Not an expert by any means, but I think the species is very picky. I lost a sizeable 'Fukuzumi' that has been in the ground for three years...suddenly this spring for no apparent reason, and having looked extremely healthy prior. I have many parvifloras that are doing well (and for many more years), but have lost many as well. It's possible that even at 4 yrs it wasn't fully established and finally succumbed to some sort of stress factor (drought, heat, pest, etc.). I wouldn't give up though, the parvs are beautiful :)

I like italmover's tapestry idea as well as Maureen suggestion of an arched mirror to echo the niche's shape. In the one pic you shared, I see a lot of contrast with the white walls, stone and wood. Not sure the current mix is as harmonious as it could be (the mantel doesn't optimal) but hard to know since screen colours are so unreliable. Would need to see a picture of the whole wall as well as the whole space.