Henning,

Do not use Sulpheric acid if it is not needed, try this AGFA-GEVAERT formulla:

bleach :
K2Cr2O7 5 g./1l. (= Kaliumbichromaat)
NaHSO4 20 g./1l. (= Natriumbisulfaat)
3 min @ 24c

claering bath :
K2S2O5 christals 65 g./1l. (= Kaliummetabisulfiet krist.)
5 min @ 24C
The clearing bath is not the same as for the Sulpheric acid based bleach!

Good luck,
Philippe

P.S. i do not know the right names in English, sorry.