I've grown perfectly healthy H. pinnatifida in hard water. From what I can remember AG manage to grow it well in their showroom tanks and the water in that area is very hard. I think also the leaves would be showing signs of chlorosis if it were iron deficiency.
Just got round to checking the water reports and yes AG water is very simular if not slightly harder than mine, Some of my other plants are showing slight signs of chlorosis which I am putting down to my ADA AS losing its acidic buffering capicity so have some Fe DTPA on its way. Tanks have been getting slightly cloudly as the week goes on after WC which I'm putting down to the Fe EDTA precipitating out in the high pH.
Thanks @Tim Harrison its your post that got me to spot the early signs of chlorosis in my tank
But I am still getting this melting of leaves on my H. pinnatifida, on older leaves had it for some time even with Full EI dose and a Luxury EI dose too. Flow and CO2 is not the issue I have, But get the Iron right first.
And here is the tank as of 1 hour ago!
Ignore the Twinstar bubbler below the lily pipe. It's not mine. I'm simply trying it out as I like the view of the bubbles it makes lol
Tank turnover/flow seems a tad on the low side with the lower plants not moving much at all, having a lot of plants ( which looks good OFC) does reduce the turnover in the tank which leads to flow issues and as @ceg4048 tells us Flow is King in the high tech tank