Charley is chubby but Summers is thin

[Miss Bad Wolf 23]

I have an interesting problem with my two Goldie friends.  Charley is fast becoming a chubby egg shaped orange and white goldfish, while Summers is staying a slim black moor.  I know that Summers is eating some as he is still alive, but I know for sure that Charley is eating too much.

I am concerned that Charley is over weight by an ounce or so (or maybe a fraction of an ounce as I have no way to weigh a Goldie).  I am afraid that Summers is not getting enough to eat.

I am getting iCloud errors so unable to upload pictures of the two goldies.  Probably will be able to upload them when I get back home or at least take new pictures.

Is there any humane way to make sure Summers eats more but Charley eats less. I could take the net which is at the bottom of the aquarium (yet again) and net Charley until I see Summers eat some but then Charley might think it is animal cruelty.

[koko 14,315]

Can you feed on one side then little bit on another side? 

[Acro 667]

If you teach them to hand feed, you can control exactly how much each fish eats.  It's actually rather easy to teach them to hand feed, even blind goldfish are easy to teach to hand feed.

[Acro 667]

If you need tips, let me know!  

Edited January 14 by Acro