Fertilizer, transplanting, fish fert

A question from a fellow grower:

First of all I wanted to say thanks for providing amazing quality fast growing seedlings. In 2 days it was ready to put into potting mix as they started germinating in my cup asap. I use well water and I am not sure if it loves the nutrients or not but it is ‘hard water’. PH is pretty neutral though.

I am noticing so many different opinions on NPK levels and when to use them. I’m also finding it hard to determine which fert to use.The problem is I heard that MG fertilizers are bad because they leave a chemical taste. I am starting from indoors and moving to outdoors potentially on a secluded balcony and want to know when to migrate this little lady to the outdoors.

The plant has started growing its jagged leaves but I am using a half filled red solo cup as a pot, and some potting mix to start her off. When do I migrate this thing to a bigger pot if I can’t see the root system? Is there an easier way to see by number of leaves?

Lastly I have some fish fert 5-1-1 like you mentioned in your guide but I was also reading that they might contain levels of mercury that could be harmful for your body. I wouldn’t want to do anything. This is my first attempt at anything like this so any advice would be beneficial.

Potting soil mixes usually have dense bark chunks. “The usual hardware store stuff.” Try Promix. Very root freindly, but very low nutrients. Just add a little .

Thanks for the information rjw.

When do I use the promix and where can i get it? You said just add a little is this referring to the fish fert (liquid)?

The question was in reference to the mercury levels and how that could be bad for you if ingested by anymeans overtime.