You need to fill out the troubleshooting form first off. Second, do not take any advice until you fill out the troubleshooting form. Third, fill out the troubleshooting form.
You have given virtually zero information for anyone to be able to begin guessing at what may be wrong.
Fourth, do not spray your plants every day w/ neem.

DWC? What are your water temps? Go fill out the form. Otherwise you are not going to get much help, and any advice you get will most likely not be very helpful, and if you follow it, may in fact compound and create brand new problems for you. It may be that you have more than 1 problem.
My 2 cents.