Re: po4 dosing
Yes, 1-2ppm is a good range, we used to be rather conservative with PO4, these days folks have really gone up rather high, but Green spot algae goes away also, that is my personal most hated algae of all.
Crypts like harder waters, higher GH's and traces, K+ as well.
Many of outr memebership locally have been keeping high K+ levels 20-50ppm for many years without issue.
Submersed growth requirements are different than the emergent Crypt growth, I do both and they work for different reasons.
TMG is available from BigAl's online for 49.99 for 5 liter jug.
It has a different chelator than Flourish.
More copper also.
I've noticed a nicer sheen on the plants than with Flourish.
Holes means either low K+ or NO3.
Better coloration is generally a trace issue.