Accidental Snail Eradication

[Fenrir]

So I am having an issue I have now had most of my beloved rams horn snails die on me. My Nitrates are close to 0 as well as nitrites and ammonia. The only change I started doing was dose API leafzone for an added boost of potassium and iron 2 times a week 20mls each time, once on Sunday and once on Wednesday. My complete dose of my tank is 8 ml. of Easy Green and 20mls of leafzone Sunday and Wednesday. Before adding leafzone I saw the snails were thriving noticed eggsacks all over but never noticed babies really but they might be hiding in substrate who knows. My plants started getting pin holes and and my Java fern was unhappy so I started to add the leafzone to bring that to balance. Soon after though I found my large rams horns to start passing away then noticed young ones as well within the past 2 weeks and have no understanding to what is happening. They were my main fighter against brown diatoms and I noticed that with them gone the Diatoms are coming back. Any thoughts?????

[Colu]

I have never used leaf zone but if that the only new thing you have added it probably the leaf zone that has kill you snails