Soft water Wills, been with me a couple of months now - no obvious signs of stress - are you sure of ID please ?
And yes - Crispulata, grows slow growing but well worth the wait
Seems you are correct on ID Wills, sorry about doubting, the research implies ok with tetra's which as you say are soft water fish -
" above are just a few options. There are tons of fish that would be great with Dwarf Neon Rainbowfish. If nothing above has caught your attention, try looking into common fish such as platies, mollies, tetras, and rasboras.
Pearl Guaramis grow to about the same size, and their pearlescent swirls would be a great contrast to the electric blue of the rainbowfish."
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