So I'm Worried I have TMV - Please help

My plants were growing great so I decided to sprout some additional (bag) seeds. Well a mutant grew up with horrible twisted discolored leaves and now a couple weeks later all of my plants have some really screwed up symptoms. Blotchy, brown, and black leaves all over.

I'm growing in soil from seed. No nutrients until a couple days ago when I tried to solve the "problem". Still in veg with the oldest plants around 6.5 weeks. I tested the pH of my water seems to be at 6.8 without nutrients.

I have a bunch of pictures here. All from before applying nutrients, the plants are no better now regardless of the nutrients. I wish I could say it was a Mg problem but every single plant has the same problem and some were planted in different brands of potting soil.

They were under CFL but I moved them to 600w MH just after the first symptoms began to show. Temps used to be high in my CFL setup, around 80f-85f, but I improved the temps after getting the 600w MH and the temps are now ranging from 70f-80f. Humidity used to be low, around 30-40%, now it's around 50-60%.

Images are attached, but this is my first post and I'm not sure what order they are in. Some are of my older plants, and a couple are of the mutant (it's the smallest one with the nasty copper colored leaves).

PLEASE anyone with any experience with this chime in.

Generally you do not see TMV kick into action until you switch to flowering. Plants become light sensitive, some leaves begin to distort and discolor, plants become heat sensitive and then the leaf drop begins around week 4-5.

This looks more like some other form of pathagen I am not sure though which one. Have you tried any anti fungal sprays?

What is the feeding regime you have been using to date?

Hi Jonas, thanks for replying. I water the plants with tap water (sits uncovered for at least 24 hours first) every 3ish days, when the soil looks and feels dry.

This problem began approximately 2 weeks ago, spreading up the plants from the bottom up, primarily affecting fan leaves. Overall growth has slowed considerably even on the tops. I have not tried any fungal sprays at all. I have been reading every night trying to diagnose the issue, but I am falling short on solid conclusions.

When it first began I thought it might be a Mg deficiency, but I did not have a chance to attempt a remedy until 4-5 days ago when I bought a beginner's nutrient package (http://www.htgsupply.com/Product-Technaflora-Recipe-For-Success---Starter-Kit.asp) and fed them once with the recommended veg combination. Since then I have only watered them once with the plain tap water (Aug 3). I have not seen an improvement, the terrible (necrosis?) continues to spread.

The inter-nodal branches are not yet affected (visually). I have been considering taking cuttings from them to attempt to preserve some life. Does anyone have an opinion on this approach? I'm worried they'll just die completely and I'll be left with nothing. On the other hand, the cuttings/clones might be affected with the same problem...

Can anyone recommend a safe fungicide for me to use? I found something called Oxidate, made by a company called Enviroselects. Does anyone have any experience with it?

make sure its safe for use on vegetables. thats all that is really important, because yo will be intaking this plant

it could be the water tho, tap water could cause all sorts of problems

Thanks rocknratm, can you tell me more about the possible tap water problems? I checked the pH and it seems to be okay, around 6.8, 7.0 at the highest. I've heard of something called ppm and "hard water " what exactly is that and how do you test it?