Grey/murky CS

Been having a difficult time with my CS maker lately, wondering if anyone has any ideas. Couple months ago (last time I used it) I made some gorgeous looking golden CS, by heating the water a bit first, using a dollop of previous batch for starter. Now... very strange, I'm getting what appears to be VERY strong CS with no golden color, with tendency towards grey/murky, lot's of black residue on the bottom. Im not very experienced with the adding of h202 but when I do, instead of it having a "clearing" effect, it immediately goes much darker, ending up dark brownish, not attractive at all... I have a feeling this is really strong stuff so imagine I need to cut way back on the time... but why won't it turn gold? I guess that isn't even really that desirable anyway, mostly curious why it's changed. Thanks!