Hello everyone, how is it growing? First of all, I am a new poster and thanks in advance for letting me in :) but I am reading here for years and learnt a lot. I got quite a few grows under my belt now, from terrible to acceptable grows I went through it all, including nearly any pest, fungi, deficiency there can be.

Before I come to my problem, I come to my setup. I use a mixture of HPS 400s and Mars LEDs TSW2000 (around 300W I think). I currently grow Autoflowers to maintain constant VPD +-. To be more specific, currently I have some Ethos x Happy Valley Seeds (Pineapple Diesel, Pineapple Daddy, Pineapple Runtz, My Thai, Easy Button, Everglade OG) and Barneys Farm (Lemon Haze, OG Kush, Purple Punch) all autoflowers. I use 11L plastic pots (the square ones) filled with Coco that are standing on small insulation plates for constant temperature. I used Coco for years, and always rather cheap bricks. I tried different bricks, from Ugro with and without Myco, to Advanced, to NDL and they all worked fine and I always mix them. They all come pre-buffered and the only thing I always do is give them a very good flush, but I do not buffer them anymore with CalMag as I used to. Right now I am in week 4-6 from seed and I feed the full Canna regime: 4ml/L Rhizotonic, 2.5ml/L Cannazym, 4ml/L Coco A+B, Calmag Agent 1ml/L and additionally powdered Silicate from GHE at 2g/10L. I lower PH with GHE Ph-. This recipe works perfect for me always. Of course in the beginning I use less A+B, but the rest always stays the same. In flower I will add Booster and Pk13/14. My PH is always between 6.0 and 6.2. I handwater about 2,5L per pot every other day and always have 20-50% runoff. My temps are between 24 and 27 Degree Celsius tops and 35-55% rlhf currently. I never had even the slightes defficiency like this.

Now to my problem: This time I added into my mix of different brand bricks also the Ugro Organic Coco Bricks, which I only found out afterwards is unbuffered. I already suspected then I might get small issues with this. Now, only some pots have a small portion of it in them, but it seems to be still enough to give them a slight Calcium defficiency here and there on the bottom leaves. Especially if I do not water every other day. Last week I could not feed them for 4 days and it got quite bad quick. With correct feeding they proceeded to grow healthy and it did not spread further a lot, but still very slightly it did spread. Of course I want to tackle this now asap and I am wondering what is the best way to proceed. Should I continue with same feeding and will balance out? Should I use same feeding but water more frequent with less amount? Should I add more Calmag to the mix? Should I water once with Calmag only at high dosage and wait a few hours before feeding normally again (if so, small amount without runoff or with runoff?)? Should I put the pots in something and really soak them with Calmag? I dont like to add pictures, but it is the typical browning spots you see when you have either Ph swings or Calcium lockout on the lowest leafs, only on the big ones and so far it did not wander further up.

Thanks in advance to every Coco fiend that already had the same issue, love you