Yellow spots on leaves during vegetative stage.

We are currently growing plants indoors under a 1000 watt HPS, they are receiving 18 hours of light and 6 hours of darkness daily. Watering once every 2 days or when dry. Using Cannazime, Canna-Bio Vega, and 0.5-0.5 NPK ratio Tea mixture. They are currently in the vegetative state. They are in an organic humbolt potting mixture.

I noticed in the last 2 days some yellow spots have appeared on the leaves, they seem to appear suddenly. There are some burnt leaf tips that are curling upwards, yellow to brown. They don't show any signs of spider mites or any other pests.

We've been looking online at various nutrient deficiencies but aren't clear what exactly the problem is here... Any advice would be greatly appreciated.

Here are pictures we took this evening of the poor little plants. It does not appear to be affecting all the plants, just a couple of them.

Hey Green Valley - not sure if this is your solution but HPS is best for flowering. Is your light fixture switchable? If so get an MH bulb while you veg. If its not switchable you might consider some 6500k fluros while you veg and save your monster HPS for flowering monster buds! I'm not sure of the n-p-k ratio of those nutes you mentioned but you can try cutting back on them and seeing how they manage - if your plants are young it may be over kill.

hey valley gal my friend has the same problem we think its either part of the genetics or enviroment issues to much heat or stress but if the budslooking good then i wouldnt worry, try using super thrive i find that helps alot

oh fogot to mention its seems you feeding them to much water them when it gets to dry and feed them every 7days hope this helps. if you need any further help please get in touch

We raised the light and used a little epsom salt in the water to help with possible mg deficiency... read a little that indicated the ph might be a smidge too high... its at a 7.5, should be between 6.5 to 7... we're going to try correcting that with hydrochloric acid... we'll see what happens and I'll update y'all.