Hello bud,
I do not, just plain water in the res, I water in any feeds I feel that the plants may need every week or so. Ill usually just do microbes, molasses or fish, enzymes , traceminerals, humics and fulvics sometimes some micronized kelp etc.
Then every month or so I top dress bonemeal, malted barley seed meal, soft rock phos, gypsum, kelpmeal, rock dusts etc. Mixed with worm casting and spread handfulls over the mulch. By the time I add another top dress, the top of the soil is somewhat exposed again, So ill add more mulch over the top-dress to get the area more active with the microbes.
Mulch is really effective when you are reliant solely on microbes to feed the plant. Mulch definitely helps with water retention, but people think mulch gives you gnats. So its really up to you and your experience with it.
Generally any unwanted pests are a result of unbalanced nutrients supply and over watering.