My seedlings are 10 days old and this one has started coming up with a brown spot which is getting worse!! Can anyone help me on how to prevent this?? Please! This is on the lemon kush and I think it's starting on the others.
Give us more info on the soil and nutes and such bro. Could be anything without that info. Sent from my iPhone using Grasscity Forum mobile app
I'm using Levington John innes no1 soil just now, was going to get biobizz light mix and all mix but I germinated the seeds and the biobizz soil got cancelled etc so had to get that other soil in an emergency I am using a 400w hps duel spectrum light and I am growing five plants(1 og kush and 4 lemon kush) in a 80x80x160 tent, I have the light on a 18/6 light period and I'm not using any nutrients atm. Any help would be appreciated bro, can upload more pictures if needed✌
Is it happening to all of your plants or just this one? Do you by chance know where the humidity is at in your grow space? Sent from my iPhone using Grasscity Forum mobile app
Well I think it's only that one but I'll show you the others! It kinda looks like its starting on them aswell if you look close! I think it could be the soil tbh! And yeah the humidity is roughly 35% and temperature is 40°C here's a picture of the other 4
It definitely is the start of a calcium deficiency. First make sure your waters ph is right 6.6. Take a small solo cup and cut slits in the bottom, and then fill that cup with the medium you are using. then pour (2) cups of ph 6.6 water through that into a small container, then take a reading of that run off and report back here. Also John Innes no1 is not great for seedlings, really its better suited for flowering. In other words it has way to much phosphorous, which can cause a potassium lockout in younger plants, which can trigger a calcium deficiency. To much phosphorous makes most all the salts the plants needs to become immobile, in the ph 5.8 - 6.8 range. A good veg soil mix should contain for every 1% nitrogen > 0.333% phosphorous > 0.666% potassium. Or an easier way to look at it, using whole numbers... for every 3 parts nitrogen, you would add 1 part phosphorous, and 2 parts potassium. I have an old soil guide that says John Innes no1 is NPK 4-3-8 and that mix contains to much phosphorous and potassium in relation to how much nitrogen that it contains.
I agree with the above. I suggest to do a transplant into slightly larger pots with a better medium since it's looking like it's close to time to transplant anyways. May take a few days to pick back up and I don't believe that the brown spots that are there now will ever go away so just keep an eye on the new growth after that. Fox Farms Happy Frog is a good soil for seedlings and smaller plants, I'd find that or something very similar. Sent from my iPhone using Grasscity Forum mobile app
I'll keep you upto date tomorrow as I'm away to head off now but before I go could I just flush it well or use cal mag to sort the problem?
Okay cheers bro! I'm away to head off now but I'll post an update tomorrow morning and try sort everything out! Cheers for the help guys! ✌