So Hydrogen Peroxide will not harm the plants? Do you happen to know the amount per gallon to use?

No it will not harm them, they will love it! 1 - 2 tablspoons per gallon. I use just 1. I am conservative with everthing but light. More light less of everything else yeilded me 7+ounces.
Oh wait your doing hydro. The amount of H2O2 could be different for you. IDK Start with a capful. depends on your res size.

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Should I just put it in the resovoir or spray the base of the plant where the mold is or both? Thanks for all of the info by the way.

Spray it right on the mold to kill that.

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diluted or right out of the bottle.

You can kill the mold with it stright up. A couple squirts will do it. Just like if you put it on a cut in your skin, it will foam up when it hits the organic material (the mold) and you can see that its working.
Hydrogen peroxide is a powerful oxidizer that can be used to destroy fungi, molds, bacteria and other infectious agents as well as some pollutants. Adding it to your water helps plants by destroying infectious agents and by adding oxygen to the roots' environment.

Hydrogen peroxide is an essential ingredient in maintaining a clean growing room. It replaces chlorine bleach, which is antiseptic but harmful to breathe. When added to reservoirs, hydrogen peroxide slows the growth of algae and other water organisms so that trays and utensils need to be cleaned less frequently. Soil and water borne diseases such as pythium and other stem and root rots occur at much lower rates in hydrogen peroxide-enriched water. Hydrogen peroxide works because of the oxidative reaction, so micro-organisms are unlikely to develop a tolerance.

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brown leaf tips signify nute burn,replace existing nutes with correct cf & ph,give a flush with ph adjusted water for a day or two first,mould,use h2o2 as said previously to remove,400 hps at 12" might be to hot (unless air cooled) and lead to lumen burn,edge of leaf will curl upward slightly.
temp,around 80f is o.k. and try to keep the night time temp no more than 10f below this.
droop, i think most people notice that towards the end of the light cycle plants tend to do this(they prepare for the dark period)
ebb & flow,i use this method (deep ebb & flow), i place the rooted rockwool cubes (with the plastic surround removed) into the container filled with clay balls(covering the top of the rockwool blocks), i flood the container for a few seconds before the pump turns off( floods times vary depending on the stage of the plant)
i would also strongly suggest to have a good air pump running 24/7

I am having the same exact issues with my plants......They are now at 49days and12days budding. They started under a 250hps and now a 600 hps. Same results. I noticed as the nights became cooler the drooping became more frequent and more extreme. After the lights go out there is a 8-10 deg. drop in temp. I was assured, by local grow shop owner, it is a normal situation and , as long as there is not a drastic temp change, the plants will be ok. it does slow the growth a little, but not enough to lose sleep over. All i know is they are growing big beautiful budds , still growing rapidly and droop more than the plants in ur pics. and the fugas/mold/whatever is almost unavoidable on the rock wool. good luck.......and they will prob be just fine.....