Reddit reviews Nature Aquarium: Complete Works 1985-2009

Test kits aren't a bad idea; but yeah. I can see how that might come across as preachy.

I wouldn't recommend CO2. CO2 is kind of fiddly; there's all kinds of fish-killing potential with a pressurized CO2 setup. If she's not up to using test kits then CO2 is probably not a good idea.

Have you considered books? I guess most people go online these days; but a book can actually be really nice to have. This one is neat; it's got colour photos and (really) short caresheets for most fish (and plants). This one is awesome if you want to learn how planted tanks work. These ones will make you feel completely inadequate about your fish tank (but are good inspiration for aspiring aquascapers).

Dang they want to charge me $36

Nature Aquarium: Complete Works 1985-2009 https://www.amazon.com/dp/0793806496

If you don't want to listen to me, maybe Tom Barr will convince you. He's just some nobody biology professor with a BS in aquatic biology and an MS in botany and Ph.D. in plant sciences who created the EI fert method. What the fuck does he know?

http://www.plantedtank.net/forums/11-fertilizers-water-parameters/68475-too-many-water-changes.html#post631290

Another real dipshit, Takashi Amano recommends 50% weekly as well in The Book. https://www.amazon.ca/Nature-Aquarium-Complete-Works-1985-2009/dp/0793806496