Colisa lalia & other fish question

[Turin Turambar]

I thought about getting a pair of Colisa lalia. However, my tank has 60 litres and I already have these fishes - 2 rams, 4 Rasboras, 6 Neons, 2 small gravel cleaner catfishes. It's 14 fish in total. I thought maybe it would be too great to add 2 other fish, but again they are all small fishes. However, my tank functiones great so far and I don't want to be overstocked in any way!
The only thing I had in mind was that Colisa lalia are labyrinth fish and they eat considerably less than others, so I thought they wouldn't pollute the water that much.
I have the self-powered external filter wich filters the water for about 400-450 liter per hour.
But I don't want to be extremely stocked - I want the fish to have space for themselves, to achieve normal growth.
What do you think? Should I get them or not?

[ChilDawg]

While they are labyrinth fish, the only significant difference is the fact that they can take oxygen from the surface. They still eat a lot and create the same amount of waste. I think that, since, by my calculations, your tank is already overstocked, you may want to get another tank before getting gouramies.

[dbcb314]

what calculations are used to figure out if your tank is overstocked?

i wouldnt put the fish in there, thats just my opinion.

[ChilDawg]

I do somewhat the 1"/gallon rule, but I make several adjustments mentally to account for the fact that few fish actually have the build to make the 1"/gallon rule work.

I also have a good feel for what fits in which sort of tank and what the aggression levels are for some fish. I don't know as I can say the complete calculation process, but I have a pretty good eye and head for what works and doesn't.

[Turin Turambar]

The tank isn't overstocked yet - all fish have plenty of space for swimming, they are all healthy, and above all - they are growing.
The rule 1-2 litre per centimeter isn't always right, because Neons, for example, are 2-3 cm long, but only about 8mm high.
But even with those rules applied, all of my fish are about 44cm long and 60/44 = 1.36 litre per centimeter.

But no matter what, I think I won't get the Colisas as I don't want to disturb equilibrium.