Help save my drosera adelae!

[flytrapsandmetal]

I am struggling to revive my drosera adelae at my workplace. Originally we found it was receiving too much light. Then it acquired Spider mites. We moved it into a covered aquarium with humidity around 60-75% and it began to improve. It's slowly beginning to decline again and we are wondering if it might be something fungal/bacterial, if it's root rot, or something else we are completely unaware of. I have photos that I can attach with time stamps. We water using the tray method with RO water, our potting mix is 1/1 peat and perlite, we have never fertilized the plant (it stays outside in spring/summer so it has naturally collected nutrients at minimum in its lifetime) and it gets 16 hours of light and 8 hours off. Thanks for any help!

Link to photos if photos aren't showing up: drosera adelae

 

[bluemax]

My best guess is that the soil might be toxic from the spider mite treatment, or just bad from other causes (age, etc.) I'd remove the plant, rinse it to remove any residue (assuming it's been sprayed) and put it into fresh soil. Then I'd temporarily raise the humidity a bit with a clear plastic bag or other means. 'Hope this helps. I'd also remove a leaf or two and put them into a glass of your purified water and under the lights to wait for new plantlets to form - just for insurance. Good luck!