Mana spreaders only send mana after they have a certain amount of mana themselves. And one daybloom doesnt produce a lot of mana to begin with so it could be quite some time before you see mana in your pool.
Pretty much this ^ Also, the moment you have enough mana make an endoflame for a bit more stable mana production as it is cheap (only uses items that burn like coal, wood, etc.). Dayblooms provide very little mana, need daylight and they will wither away (disappear) after some time.