heavy bioload

So I already have a Citron goby and firefish in my 15 gallon tank. I already have a pink streaked wrasse on the way but was thinking of getting another Citron Goby to pair them up. Do you guys think this is a good idea or is it to much bioload for my tank?

Let's start with the history: I started a new tank (65g) about 3 months ago (red sea reefer 250 g2) - I skipped the cycling by using liverock & corals from old tank. - Inhabitants since day 1: 5" medium Powder brown tang, 3" small blue hippo tang, 2 clownfish, 1 damsel, 1 bi-colour blenny and 1...

I have a 50G where I mostly keep LPS and tubastrea. But I wanna keep NPS soft corals (i.e. red finger gorgonian) later down the road, so I'd consider this a heavy bioload 50G. ;DeadCurrent setup and problem. Originally, I only used a skimmer for mechanical filtration so I got an oversized one...