I purchased a pack of 3 seeds, and one of them didn't germinate. I must admit this is discouraging, and I believe reputable seed banks should address this by providing guarantees to us growers. I'm not wealthy, and when a seed doesn't germinate, it feels like I'm wasting money.
Regarding the fertilizers, they come in powder form, but I didn't see the option to measure in grams, so I used milliliters instead. The iron supplements I use are effective; I even found it strange not to have Plant Prod around here. It's a very affordable Canadian fertilizer that delivers good results. Many brands don't want you to know about this fertilizer. Look it up and let me know what you think.