Is my oranda goldfish going to grow a wen?

Is my oranda goldfish going to grow a wen? I have a 29 gallon tank, an aqueon pro quietflow 75 HOB(for up to 90 gallons), with a heater holding temperature (72 degrees Fahrenheit). My fish tank has a Black Moor Goldfish and an Oranda Goldfish who seem to be doing fine and are happily swimming around. I was just wondering if it has stunted wen growth maybe?
Parameters:
NO3-: 0
NO2-: 0
pH: 7.5
kH: 80
GH: 30

they eat Omega One Fish Flakes for Orandas/Fancy Goldfish, Tetra Brine Shrimp as a daily snack, and HikarI Sinking Goldfish Pellets.

Am I doing something wrong?

In inches, I would say they're about 4.5- 5 or so inches each and I didn't add any decorations in the tank to give them as much space as possible to swim in. They look so small in the tank lol! xD

Also, would it be a bad idea to add one more fancy goldfish to my tank? Keeping in mind that this tank isn't their forever home lol I will upgrade in a few years ^_^

 

How old are they?
I wouldn't put any more goldfish in this tank it's overstocked as it is.
orandas get big, I personally wouldnt keep them in anything smaller than a 40 gallon breeder.
if you aren't too attached to them, you would do good to rehome one or the other.

 

How old are they?
I wouldn't put any more goldfish in this tank it's overstocked as it is.
orandas get big, I personally wouldnt keep them in anything smaller than a 40 gallon breeder.
if you aren't too attached to them, you would do good to rehome one or the other.

They're about a year old right now. I have read multiple articles saying that a tank should be 20 gal for the first fish and then 10 gallons for each fish added. I don't plan on re-homing them and I am upgrading them to a 40 gallon tank (or 55 gallon if I can find a good deal on one) in a few years when I no longer live in an apartment complex with a tank size limit.

 

I believe that's pretty good growth on your Goldies.

 

I also wouldn't add more Goldfish to this tank. Even Fancies can easily reach 8 inches, and that doesn't leave a lot of swimming room in a 30" tank. I've heard that rule as well but imo it should be a 40gal minimum + 10-20 gallons for each fish.

At 5 inches I would expect some Wen growth, but for the most part I've only studied Ryukins, so I'll let someone else comment.