I agree with Weedhound, 1000 or even less would be better at this point. Also I dont use more than 1 tsp of hydrozme per gallon.
Even if your plants were completely healthy 1000 ppm would make them flourish.
Once you figure out your system you will have a feel for how fast the ph and ppm are going up or down.
I know with my system I have to put a 1\4 to 1\2 tsp of ph down every day or so inbetween nute changes.
When your trying to diagnose a problem decrease the nutes etc. and increase the oxygen, till you figure out what the problem is.
If you decrease everything except oxygen and your plants come back looking better then you know your giving them too much of a good thing.
If you have a vented hood or have air blowing over the tops of the plants. Lowering the light as close as possible is a good way to get your plants to start thriving again.
Good luck.