I use HP Promix Soil Indoor Strain is Ice 36 days old watt 4 24 wats daylight and 2 42 wat daytime cfl so 178 wats 1 inch from light sometimes closer fed everyother watering and using a 20-20-20 half strength cuz the plant was yellowing than cut down to 1/4 stregth. temps 80-85 2gal pot Any help at what might be causing this would be a great help, ty for ur time.
Looks like the start of PH spotting. Flush the plant with water at 3x the volume of soil. Are you using tap water, or RO/distilled water? Do not add any more nutes for now.
Most likely spotting due to Ph issues. Do as Don suggested, and flush the medium well. If that doesn't help the plants within 4days read below... Possibly some foliar spotting. If the spots expand, and cause more yellowing bacterias, fungus, and nematodes are a few that can cause this condition. Check your foliage with a microscope (30x-60x) on the top as well as underside of the foliage with symptoms. If its notfixed the leaves can yellow more, and drop from the plantThis could also happen from cool/cold water falling on the leaves if they are hot from the lights, and don't spray your foliage within 4 hours of lights off because warm, moist, dark conditions are ideal for fungus and mold to infest. If you have a better camera that you can switch to the "flower" setting so you can get super close to the spotting, and it will still be super clear pictures. That would be helpful to better diag. your plants, because we only have what you say, and the pic's to help you, and you have a better look at your spotting problem to get a better idea.
At this point, unless your tap water comes out above 200ppm TDS, use it for watering. If it is more (like mine is 255ppm) cut it with RO water (drinking water says "purified by reverse osmosis" on the label, really small.). MIX 50/50 TAP/RO, not filtered tap and RO, filtered tap defeats the purpose here. Plants do need chlorine, despite what some may think about it being bad. Tap water contains Calcium, iron, and chlorine. Most Nute companies leave these out of their formulas because they assume you will be using tap water, and then you end up with what I will call "Soil Grow Hydro Syndrome" (I kinda like that ), where you need to buy fixes for iron, magnesium, and calcium deficiencies... and that still doesn't give you the chlorine needed. Straight RO is for sprouting seeds, young seedlings, and flushing in the end. All where nutes are not needed.
Couple things I just either wanted to suggest or clarify. I have been using Ice for awhile, easy plant to grow, but I am still getting it dialed in as it is very sensitive to Nute burn compared to other phenos that are on the same solution. They also seem to either use /need a ton of nitro during flower as there leaves will yellow before other phenos on the same solution. I would also move your lights to 2" off the top with the flouros Dont use distilled water,(I think thats what the previous poster was trying to say) RO seems to be the consensus best around here, but I have always used Tap (75PPM) since mine is so low. Good Luck with your grow bro. Please Note: "Anything I say is just an attempt to be part of "the cool crowd" and not from personal experience. Only things I have read and dream about. I have an active imagination everyone says"
Go on ahead and defeat the purpose of using nutes ferts with your tap water. A lot of bacterium and living organisms are in them. And Tap water kills them and makes their purpose useless. RO and 5 ml CalMag per gal. for the basic template.