Marine algae extract and silica

Last week I bought some heavily discounted fertilizer at an auction. I have 20 liters of Green Planet Ocean Magic (marine algae extract) and 5 liters of Power SI Bloom (bioavailable silica).

I'm thinking of using this to water my tree seedlings (Swedish aspen, pine, spruce) and as well my vegetable garden. And maybe even indoor plants (?).

Any advice, suggestions, do's and don'ts?