Clockwork-crow

Hello all! So, i have a 15 gallon tank full of stem plants that's on its way out of a cycle wobble, and i was hoping by the end of May to have this stocking 9x Celestial pearl danios 10x Corydoras habrosus 1x sparkling gourami I know this is approaching the limits, the tank is currently running a 4.3 inch sponge via a Tetra APS150 and a 2 inch sponge with a Tetra APS100, so i was curious if anyone thinks this is a terribly bad idea or in general had stocking ideas that include sparkling gourami and cory habrosus. (I'm open to rehoming my current 6 CPD's but over the last couple of weeks they've been breeding and all of my females look very gravid, so I'm not especially keen on it)

Right but should I be using seachem prime and water changes or tetra safestart

12 dwarf corydoras + 6 CPD's in a 15 gallon with lots of stem plants, anubias, Java Moss and Java fern One large sponge filter Water change 7 hours ago, water tested 5 hours later, multiple times Wet test, new box opened last week, using prime as dechlorinator

I'm pretty sure my cycle has crashed. Ammonia is 0.5, nitrates are 0. I'm wondering if I would be better using safestart or water changes and dosing with prime and stability. Anyone have experience or opinions?