[Grah the great]

How big is the tank? Tank length is much more important than any 'bioload' rule, and in any case we cannot help you if you do not specify your tank size.

 

[Saltydog33]

Ahh crap forgot to mention the most important thing the tank is a 45 long 48".

 

[Klinckman]

I'm guessing you have a 20 gallon tank.
You have good filtration, and larger regular water changes helps along with plants to keep the water clean with large fish loads.

If you didn't have to worry about the platys breeding, i would say add the neons, however in a couple months there are going to be many more platys in that tank.

With that size tank, I would add more fish, since i love plants, but i love my fish too and keep my tanks well stocked.

 

[GuppyGuppyGuppyGuppyGuppy]

I have more fish than that in my 29 gallon and I'm 50% stocked by bioload. Nevertheless, the tank does look crowded. Get fish that swim in groups together, that's my advice.

 

[roadmaster]

Unless the platy's are all males,,You will soon have plenty of fishes.

 

[DaveP1982]

Your platys may soon start producing their own live food - I once watched a female giving birth whilst the dad hung around behind her eating whatever came out. Pretty savage..I'd say you have room for more tetras but I'm a sucker for big groups of one species - maybe get some glowlights or black neons are pretty fish - they will school together but in their own groups at the same time if that makes sense. Just increase your water change routine to more frequent smaller changes rather than say one weekly large change to help keep conditions stable.

 

[AshNeon93]

I think the inch per gallon is rubbish, depends on the fish and how you care for them, within reason of course.