[Rocksy01]

I'm not a pro but lemme give some analisys about your tank.
1. You used some plant that absorb the nutrient slowly so the amonia broken down at slow pace. Maybe you could turn down the amonia supply by a bit.
2. The wood maybe doing something with the water chem too.
3. About the GH maybe the RODI system went crazy or the mineral dosed is a bit too much.

My newbie head suggest you to put some cheap fast growing stem plant to help you fight the chem. But dont plant it, just let them suck everything from the water body. And be patient since we newbie always tend to rush things and nature doesn't move that fast.

I apologise for butchering the language.

 

[Rocksy01]

And about the dosing. What's written isn't always that accurate, every tank has it's own condition. So find your sweet spot.

 

[Rocksy01]

I forgot about that @Rocksy01. Fast growing plants such as salvinia minima, pennywort, duckweed, salvinia natans, vallisneria, etc. would be good.

I prefer the fast stem since they're easy to move to another tank. Duckweed would pain in the butt to remove.

 

[Rocksy01]

Yes it is. It gets stuck in the holes in fish nets to.

I think Hornwort would be quite perfect for this job.