Plant problem please help.

Hello fellow members.

I was hoping that my first query wouldn't be plant health related but sometimes these things just happen.

I'm currently 3 weeks into my first grow. I have 9 barneys farm blue cheese and 1 barneys farm LSD in 6" grodan delta blocks in 2 1maqua trays. I'm doing the hand water run to waste method. The grow space is a 1200x800 insulated cupboard I have built. The two trays are under 2 600w hps in cooltubes which are cooled independently. Each bulb is just under 30cm away fom the plant. The radiant heat is never over 35c at canopy height and the air temp bounces around between 23c-27c all day long. Rh is between 40-60.

I'm currently watering every 3 days with canna aqua vega at 700 ppm (tap water is 350), ph5.5. They usually take around 2.4 litres including my 20% run off. I supplement h2o2 17.5% at 1ml/litre when mixing my nutes. Like I said before all run off is discarded.

My problem is........

Yellow leaves and drooping and some weird brown patches Not all plants seem to be effected, I've put this down to different phenos needing different strength fertilizer. However they all seem to be suffering slowed growth.

Any help is greatly appreciated, thanks in advance guys

Showing signs of imbalanced ph. Bump up ph to 5.8- 6.1 with light nutes

also 35c is wicked hot...around 25c tops

The 35c is the radiant temperature at canopy height, the air temp in the room never rises above 27c. Thanks dude I'll try that but having just watered last night do you think I should do it again now even though the blocks are still wet or wait until it dries out abit and do the same again ?

water again

350ppm tap water?! that's the highest I've ever heard, although I'ven't heard all too much on other peoples taps.. But there could be something there. since you're hand watering maybe brita filter that water ( I know RO is the way to go, but it's a lil pricey)... But I've only grown hydro so I could be totally wrong. My tap is 30ppm so I'm a lil bratty/spoiled

That was my first thoughts so I asked my friend and he assured me that the areas water is fine for hydroponics. And he's grown using it for years. I have just came to the realisation that my essentials brand ph meter hasn't been calibrated since purchase almost a month ago. I will calibrate it when I get home to make sure I haven't made a very stupid mistake by feeding my plants danger drink