Check the filters on your RO/DI unit. They may be exhausted or not performing up to spec, meaning you are re-polluting your tank every time you add what you thought was clean water. Manually test the product water for TDS before adding to the system.
I just changed the filters a couple of days ago and the TDS meter shows 2ppm coming out of the RO/DI.
Check your GAC and GFO to make sure they are not exhausted.
No GFO yet and the carbon has only been in there for 2 days.
Are you running pellets? Remove them. They are not useful in a new system.
I have been running pellets, but took them off line after reading your post.
Don't add any life to the system until you can get initial water parameters under control.
Not a problem.
Dave.M