[PICS..] Curled leaves, yellow between veins, curled new growth, brown spots?

I'm having some trouble with these plants. I've tried a few things but I'm honestly stuck.

The problems:
Curled upper leaves.
Light green between veins (this started from the middle of the plant).
New growth is curled and the tips are light green.
There are some brown spots on some leaves.

There were growing fine for weeks then suddenly developed problems. The problems developed before I fertilized.

Temp: 27C (80F)
Humidity: 60%
Soil: Royalty Mix
Tap Water pH: 8.0

When the problems started, I measured the water pH and found it was high. The runoff was 7.3.

I flushed one with correct pH water, gave Canna Terra Flores nutes to 2 of them. The nutes seemed to help them a little but the problems have come back.

I got the run off down to 6.8 using water with pH at 5.0.

Yesterday I tested foliar feeding one with some epsom salts. No results yet.

Here are the pics:


Curled leaves.


Curled new growth with light green tips.


Some leaves have some brown spots


Yellow between veins


Yellow between veins


Yellow between veins


Yellow between veins


Tomato plants are also starting to have trouble. (different soil)

I hope someone can help.

The soil is Plagron Royalty Mix. Prefertilized. No problems for the first month then problems.

The images are on a web server using the tags.

looks like you have a magnesium and a calcium def, not sure if this is the cure 100% but if i were you id go get some cal mag + from botanicare, flush your plants with ph adjusted 6.5 water and then start cal mag feedings

It's been nearly 2 weeks since the last photos. I'm still struggling with this problem. Yesterday it really went worse. The leaves suddenly went yellow fast.

I tried foliar feeding with epsom salts (I did it about 5 times). I been doing half strength nutes (canna terra flores) every 3 watering. I bought some calmag and I used that a couple of times about 5-6 days ago.

I've been watering @ 6.5pH. The run off has been around 6.9.

2 days ago I watered with half strength nutes. Yesterday I had to water again, I used the rest of nute solution (0.5L) each plus just some regular tap water (pH 7.9). The lower leaves have gone really yellow fast. I don't know if I shocked them with a bit of normal tap water that I didn't lower.

I have 2 lights, 250W + 400W. The temp is a bit high, around 29C (84F). Humidty is 60%.

I'm really stuck with understanding what the problem is. I thrown some money at them with nutes, epsom salts, calmag, ph tester. None of it has really helped. I really want to find out what I'm doing wrong.

Here are the pics:

Are you watering with city water? It looks like heat stress on the upper leaves and nitrogen, calcium, and magnesium deficiency on the lower leaves or just a lack of light causing them to turn yellow. If it's city water you might be locking out magnesium with too much calcium, maybe try Epsom salt? Maybe use some calmag+ which has some nitrogen in it as well.