Help me diagnose this leaf

Just started week six. Flipped from 24/7 to 12/12 last night. Just did sledgehammer on Saturday.

fox farm notes. Sunshine advance mix #4.

This is only effecting one plan and on 4-5 leaves

any and all help is really appreciated..

mag deficiency

Thanks fattie...

When I started the grow I started with distiller water and wasn't adding any cal mag. I have since started giving cal mag but this one plant is showing the above signs...

i was giving 2 tsp per gallon of cal mag since that is what is suggested for accelerated dosages.

any advice on how long I should keep up with this dosage? Should I dial back to 1 tsp per gallon since I am now using tap or since I am now using tap water should I discontinue cal mag dosages?

I had a similar looking deficiency a while back and a RIU member here suggested using epsom salts to treat it. The problem disappeared in about 10 days. I believe epsom salts address the mag problem as fattie mentioned above. I do not recall how much I used then, but I add a tablespoon to a 5 gal bucket now as part of my regular feedings.

Good questions..my tap here is slightly hard and I still add a little here and there. I would just dial it back and use sparingly. The areas that are brown can't go back to green, but you can prevent the problem from getting worse.

Thanks gents... Looks like the next google search I do is "cannabis Epsom salt" to get a bit more edumacated on dosages...

Thanks!

I feel ya, I switched soils from FoxFarm to this soil that Great Lakes Green is selling and I have to say, this is the worst grow I've ever had as far as deficiencys go.. I liked the soil at first but I am going back to FF and not looking back..