Sailfin Pleco in 30g tank?

[litchic]

I won a gorgeous Sailfin pleco at yesterday's auction at Jack Purcell. I have a 30g tank with a 3inch bn pleco, as well as few mixed tetras and 3 juvenile angel fish.

Once I got home & did my homework, I was astounded to find how big sailfin plecos can get!!! Mine is currently about 5inches.

I'd love any advice/feedback about whether my tank is too small for 2 plecos (especially with one being a Sailfin)... if worst comes to worst I'll look at finding the Sailfin a better home.
Should I have any concern over the two pleco species fighting? Also, does anyone know ideal kh for plecos? I've seen online range of 4-20dh but don't know what that translates to in kh...

Advice is much appreciated!

[Toss]

should be okay for now. reassess the situation after he reach 10"