I bought 10 N. Ampullaria seeds online one and a half year ago, all germinated in a month, but up to now they still remain very small, less than 1 cm. They all in a small pot with a transparent lid, humidity should be 100%. I use pure peat and the tray method to keep the peat constantly wet. Temperture inside the lid is 25C. Absolutely no fertilizer added before since i am not sure how much fertilizer is needed.
Is there anyone can tell me why they remain that small after 1.5 years? And how to speed up their growing?