How often does one fertilise?

I’ve got a 20 L tank with aquasoil substrate
LIGHTS: neo helios s3 Pro+ 13 watt light
CO2: citric acid + baking soda drip set up (Ziss)

PLANTS:

- Attempting to carpet monte carlo
- Ludwigia glandulosa
- Hygrophila pinnatifida
- Wisteria
- Planning to put in fissidens and/or riccardia moss

I dont think i need any fertiliser for now due to fresh aquasoil but planning to use an all-in-one fertiliser (without iron/ but no phosphorous) and phosphorous only on another day (to prevent it binding to iron)