Still fighting plant problem

Thanks in advance for any help.
Hydro
ph =6
70 degree h20
dutch masters gold @400ppm
tap ppm 36
clones
Strain? unknown
2 - 1000hps and 1 1000hal 20"
humidity 30% upper 80's degrees
water 2-3 times daily from top
polyester and gravel

Here is a pic

Hand watered hydro?
eek.

You gotta flush your medium out real well. You've got symptoms of a serious burn/lockout problem, but your ppms are too low for good growth. Where did you get the gravel from, and how did you prep it for use?

You also need to be adding calmag with tap water that soft. I don't know the Dutch MAsters line at all, but in flower you should be able to run 1000ppm ferts EASILY without burning, so either your medium is to blame or your fertilizer isn't right for your system. Also that pic is very blurry and if you can get clearer ones of the damage, plus a couple of your overall setup showing a whole plant at least, plus proximity to lights, that would be great.

Thanks for taking the time to reply. This is my first in hydro. I did OK in peat/perlite but even then I had problems with leaf edge burn and spotting. It seemed to show up in late veg and early flower. I think I am fighting more than one problem (learning curve) I am sure at this point that I am not over fert the plants but very well may have early on as I followed the manufacture directions. I have learned more from the forum than I did recking alot of plants. The one pic I attached shows 2 plants in veg that are in DWC with bubblers. They are both starting to show the same signs. Leafs drying and brown on edges and tips. They only have a total PPM including water of around 250. I am starting to suspect the well water as at least part of my problems? Thanks again.

I am posting a reply to my own post so someone else might find the information usefull.
My burnt/yellow leafs were caused by several little problems and no one solution was the answer. Here is what I did wrong.

*Spraying the leafs with water with the lights to close.
*ferterlizing by the lable directions (dutchmaster gold) this is way to strong for younger plants.
co2 bottle ran out while I was gone and 85 is to hot without and even worse if the plant is sickly.

To correct the yellowing leafs I flushed heavly. I added CalMag to a 1/4 strength nute solution and add 2.5 cups of hydrogen peroxide. I also have started using 2 tbsp of hydrogen peroxide pr/qt of ph balanced water as a leaf spray. Seems it has many uses and benifits for plants. I included a pic of one of my plants 4 days after I started damage control. It shows one of the leafs that where burnt and how well the plant is doing since.
Hydrogen Peroxide: practical, environmentally friendly & anti-bacterial

I hope this info is usefull as my lesson was hard learned.