Yellowing bottom leaves

Hey Misher, out of curiosity, which brand of soil are you using or did you make it yourself?, you said they claim so I am guessing you purchased a pre made soil?  It could be a few things, but without knowing the soil you used it makes it a bit hard to iron out what additives it has/doesn't have. Have you been checking the pH of the water you are using? 

Some pre made soils are very good but in my experience I still needed to add the odd top dress to keep it happy. But if we know what is in it already we can help a little more. Also is it just the one leaf or is it a few? 

I may be wrong, but I don't think that is too much to worry about. Could you post a photo of the whole plant? I suspect that you have some heavily shaded lower leaves that are just scenesing. If I were you, I would (1) cut back on water a little bit (you want the pot to feel somewhat light when you lift it before you water again); (2) when you next water, add some liquid seaweed ( removed link Get a smaller bottle, it goes a long way) and a little molasses and epsom salt to your water, do this for all waterings; (3) watch for signs of distress on new growth. Right now, you new growth looks good to me. Best not to do anything drastic.

Here is a little recipe for your water:

- 1 gallon filtered or otherwise dechlorinated water (you can let tap water stand uncovered overnight, unless your municipality uses chloramine instead of chlorine - you can find this on their website)

- 1 Tsp liquid seaweed

- 1 Tsp epsom salt (get it from the pharmacy, it is super cheap. Use unscented of course)

- 1 Tbs unsulfured blackstrap molasses

Mix right before you water and use at each watering.

You can also add 1-2 Tbs gypsum as a nice calcium and sulfur supplement. You can buy this at most garden centers, but you want powered, not pelletized. If you can't find that easily at your local garden center, you can order it from homebrew stores or hydro stores.

Good luck!

You may also find this useful if the yellowing continues on other leaves: removed link

Looks like it has stopped progressing which is good, i wouldn't be too concerned now about them, the new growth looks to be coming through strong and healthy. those yellowed leaves will not recover and will eventually just die off, just keep an eye out for any further yellowing but it looks like they have found their groove.