my 3 inch ryukin appears to show early symptons of SBD, sometimes he floats on top and has to fight in order to swim, while other times he is fine. I presoak all of his foods, should i remove him away from my lionhead and pearlscale, both do not show any symptons of SBD.

Hi there burgernuts. SBD can be very hard to manage in a fish I am sure you know.
Soaking the foods are a great step to helping that. I wouldn't feel it nessasary to seperate them since it isn't contagious.
Have you checked your nitrates lately? Often fish can have this condition due to nitrates 40 and above. Of course it may not have anything to do with it, but it is always good to make sure of that.

thanks for your reply, my tank has more than twice its reccomended filteration and i also change 10% of the water every week, or sometimes about every 10 days.

btw, has anyone heard of pearlscales or lionheads having sbd, or is it mainly in the ryukin community?

and I also feed my goldfish freeze dried tubifex worms, they come in cubes, and i just cut the cubes into smaller balls and throw them in there, they soak up water pretty quickly, so I don't really need to presoak them, as i would with the pellets, but anyways my question is, is this a possible lead in for sbd?

To answer your questions about sbd and lionheads and pearlies, yes it is a common thing as well. The deep body varities all stuggle with this.

And for the tubifex worms, how long do they sit on the top? If they eat off the surface at all or if the worms aren't "swollen" from being in the water long then yes this could aggravate SBD.