Healthy leafs falling off?

Ok so lately I've seen a little yellow and brown in my leafs but I almost never had them falling off before. Then I went to my local hydro place and they told me to use advanced nutrients for the problem both by adding it to the nutrient solution and with the spray for the leafs. I followed the directions on the back of the bottle. Then it seems that leafs that were healthy and green were falling off and I would find them on the ground.

So since this started I have been using more water and less of the advanced Nutrients revive. This did not solve anything. Leafs still falling off.

Please help me.

that leaf is not a healthy leaf by any means you have a deficiency , look at this info graph https://www.rollitup.org/marijuana-plant-problems/488004-guide-nutrient-deficiency-toxicity.html

If the falling was fast, meaning rotten roots probably, check 'em out !
If not, there are too many problem that lead to leaf falling :
[h=2]Manganese Deficiency
Nitrogen Toxicity
Sulfur Deficiency[/h]Best Solution : Flush your system with clean, pH'd water that contains about half the correct amount of nutrients needed by the plant. Watch to make sure that the problem starts to clear up within a couple of days.
And of course, check out the pH (always 6 - 6.5)

The leaf shown has deficiency symptoms, which are indicators of another problem. But when green, healthy leaves fall off, as you've mentioned, it can be due several things. Drought, Light intensity, etc. If the plant is getting tall and thick, it may shed leaves it can't support, based on the amount of light. The light from a 400 watt bulb, for example, is only going to penetrate through so much flora, and the plant will start dropping the lower leaves. Probably not enough info on your plant to give any real direction as to your problem.