Can plant fert cause disease?

[oscartank]

I've recently dosed my tank with liquid sechem plant food and also added those push into gravel rooting plant fertzz, then my boesemanis have mouth rot like the next week! Coincidence? I look after my tanks well cleaning and changing water weekly! Any help would be ace, thanks!

[fishorama]

Rainbows are prone to columnaris, I don't think the ferts are to blame. It is worse at higher temps. I lowered the temp to ~76 & used a UV to help with chronic columnaris (& cyano).

[bushwhacker]

in a word no. the ferts had nothing to do with it