Protect from snails/slugs from the beginning and keep an eye especially when new growth sprouts from the ground. I found that snail/slug pellets do not give enough protection as it's just too delicious for the snails. Also, I find that seeds germinate better when you cover the pot/tray with cling film and tie it around with a string. Not too tight so the seeds don't suffocate but it keeps the heat and the moisture in. Leave it be until most of the seeds germinate and reach the cling film.
Update photo of 1 of the Delphiniums I grew from seed - which is now growing in my Dad's garden 💚 The other one is next to it 😁