Help with edges curling up, leaves curling down & inward, yellowing edges

Hey everyone, first post on the forum, too bad it's a problem

So here's my setup:

4x Jack Herer clones (2 in each WaterFarm) 2-3 weeks old
PH always checked daily and maintained between 5.5-6.5
1x600W MH air cooled light (12-14" above canopy)
WaterFarm hydro with hydroton running 24/7
2 fans not directly on plants but above canopy
Temp reaches a max of 75 and usually stays at 70 with 50-60% humidity. At night it sometimes drops to 65 for a few hours until the sun comes up and warms the basement.
I started off with using FloraNova grow 5ml/gal and when I saw it curling up, I did a day of water and then used FloraBloom Grow and FloraMicro (using the recommended doses for mild vegetative growth)

I can't seem to put my finger on what's wrong, could anyone help a fellow noob grower out? Thanks!

Also, when I filled the buckets with water today, I had to use tap because I didn't have any more purified on hand. The starting PPM was 140 out of the hose and 4 hours later after balancing PH again it rose to about 220-240

Calmag is an essential part of any nutrient regime!

So what would you advise??

thanks ill try that, I use a PH solution to verify alongside the digital just to be sure.

Ph around 6.0 like MGG suggested will help with Calmag absorption, and rule out simple pH issues. I'd still grab some Calmag nutes and start using as directed.

Ok I'll do that tomorrow. Would you suggest using something like florakleen to flush or when should I start giving it nutrients again? Sorry for all the questions, just trying to grasp all the info as to when to use calmag and with or without nutes.

I do coca so its hard for me to say >exactly< what do do with hydro, but I botanicare calmag. Its synthetic so it can be left in the reservoir without a high risk of algae. I usually add a dose about once every 2-3 weeks since calmag issues show up often, and are very common. I wouldn't bother flushing, there not in that bad of shape and you run the risk of causing more problems then you solve. If you have a tds meter make sure to keep your ppm around 600 (that plant appears to be pretty young still). Use calmag in addition to your base nutrient and feed once every two weeks or so.

You'll learn later that recipe solution like ^this^ will never be perfect, if your new the challenge for the next couple of months will be getting your plants to survive you.

No offense of course, I know what its like to love your plants too much

haha thanks yeah I know what you mean, I check on them like 4-5 times a day and hate when they're not healthy. I'll make sure to keep the PPM around 600 and 6.0 pH. Thanks for the advice, much appreciated.