In other news…today I found an issue of amazonas dedicated to licorice gouramies, and one of the articles was about their wild habitats. Quite a few of the wild habitats had absurdly low conductivity levels…one P. deissneri habitat had a conductivity of 4 microsiemens! More pure than my distilled water after it comes out of the distiller :O Not all the habitats were quite that brutal, of course, but quite a few of them were still considerably softer than the 20 microsiemen minimum listed on this site. Makes me wonder if it is safe to go that low with aquarium (and especially wild caught, which are presumably more used to it) specimens…
Oh, here’s the link (I think it may be linked to the parosphromenus project anyway, but oh well): https://www.parosphromenus-project.org/attachments/article/192/AMAZONAS%20Licorice%20Gouramis.pdf