Nitrates And Co2 Booster?

Hi all.

So in my 10 gallon I have mostly slow growing plants with 2 new med to faster growing plants added within the last 2 weeks (floating water sprite, bacopa I'm floating). everything else is pretty slow growth plants. My nitrates have been higher recently, around 20-40 ppm, usually closer to 40. I'm trying to get the plants to grow a bit faster and was gonna start adding liquid CO2. Will this increase my nitrates at all or cause increased stress on my fish? My lights are a medium strength

In my 10 gal, my ammonia is currently .25 and nitrites around .25. I know this is because the tank is a bit overstocked. I am using a HOB filter and the sponge filter I ordered for additional filtration is coming in tomorrow. I'm currently dosing with prime to detoxify the trouble spots and so far the fish seem ok.