leaves drooping at tips and curling under

This is my first indoor grow or first grow period and I think I'm having some issues, a little info, I currently have 4 plants that are in the third day of flowering and 3 plants that are still vegging that are 2 weeks old, for equip I have a 400w MH i used for veg and a 600w HPS I'm using for flowering(one fixture different bulbs) that are 32in away from plants, the grow space is 4x4 with mylar on the walls but its not all bunched up, I don't have 2 set ups so when I needed to flower the older plants I put the younger 3 in a different room under 2 4 foot fluorescents that are 3-5in away from plants and is working fine. for testing I bought a meter that's a 4 in 1 it checks ph, moisture, light, and fertility, I was using tap water at first and the ph was 6.5 and when I tested all the soil all the pots were 6.5 so I don't think its a ph problem, the temp is always at 74-76 deg so its not too hot or cold, the humidity stays between 30 and 40% during veg and 40-50% when I went to flowering. I'm using miracle grow potting mix 3 month release with moisture control(after research I probably won't use again) I water every 2-4 days but I think it might be too much because the soil always feels moist even before I water but I still do because I know how long its been and feel they need it, I also mist them with a spray bottle, at first I misted them a lot a few times a day but now only every other day, I also just switched to distilled water today but haven't given them any yet accept for a small misting, a friend gave me a bottle of liquid karma, flora bloom, and bat guano I have only given them liquid karma twice I mixed 1 oz with a gallon of water and gave them each 200ml last week once and then yesterday I gave them 300ml each other than that just tap water, I haven't used the flora bloom or bat guano yet but I think I should because I'm flowering now.

The Problems(with pics)

Like I said there are 4 plants that are 3 days into flowering there is 1 plant that looks the worst the new leaves at the top are curling under and some of the leaves are just drooping at the main vein on the leaf as you can see in the pics, all the plants new growths seem yellowish in the center but it could be the color of the hps that is throwing me off, and there are little marks that kinda look like scratches they are tiny, from reading the threads it sounds like thrips I hope not but a lot of people said MG has bugs in it, and all the plants leaves look a little darker and dull at the tips and have some kind of white residue at the tips which I think is from me misting them(I have hard water) that rubs right off you can only see it if you look very closely. then on my new plants that are 2 weeks old I was checking them out last night and on one plant there are a couple leaves with spots that seem to go right through the leaves like little holes but there are only a couple, please look at the pics and let me know what you think or see if you notice anything I don't, thanks

and will someone tell me if I should start using the guano or flora bloom for the flowering plants and how much like per gallon of water in ml or oz? and how often I should fert? and how much? sorry so many questions I just want to know all I can

You may be watering your babies too much... if your your soil is still moist you don't need to water them. Too much water could cause problems such as slow growth and root rot. Water them when needed. Your plants will tell you when they need water. Trust me. Make sure you have even water penetration when you do water your babies.

Make sure the temp of your nutrient solution below 69 degrees to help prevent deadly verticillium and pythium wilts. These are deadly diseases can be kept in check if your water temp is below 69 degrees.

During flowering; inspect for brown rotting roots and fungus gnats. If brown rotting or discoloration has occurred, decrease watering until roots have the proper amount of nutrient solution.

Be careful not to over fertilize your plants...most soil mix already has fertilizer in it so it's easy to over do it....Fertilize every 3rd or 4th watering. Have you flushed your plants before flowering? You may have nutrient buildup if you didn't. Flush monthly and 2 weeks prior to harvest.

Do not use time release fertilizers....they are very difficult to control and nutrients problem can occur if you are not extra careful.

Since you have leaf curls and or burnt tips...this tells me you may have over fertilized plants resulting in salt build up. This is why a ec/ph meter is useful to have on hand.

Try flushing your plants!!!

Check your ph level...ideal is 6.5 -7.0

As far as how much fert to use....just follow the instructions.

Hope that helps you....Good luck

Thanks for the advice I'll try flushing them and watch how often I water, and I got the ferts from a friend in water bottles because he has big jugs and just gave me some out of those so I didn't get any instructions it sucks, and I'm definitely never using MG again I'll get some regular stuff I read in another related thread someone recommended some fox farm bug free stuff so I'll go to the store and see if they have that for next time, and should I flush and then give ferts or just flush and leave them alone?

Fox Farm is good stuff... ferts with instructions is best (smile). Flush first and provide ferts after 2 weeks at least. Monitor closely during the two weeks.

thanks for all the help, I'll get a hold of my friend and see if he will write down the instructions for the fert, thanks again.

cal if you know what ferts he gave you just look up the brand on line and you will find the instructions. good luck~

ooo. kitty knows what she's talking about.