Fastest way to cycle biomedia in a HOB filter

I have the biomedia currently in the sump of my up and running 40B w/ 20g sump. It been in there a week. Today something doesn't seem right with the 40B. The water parameters measure fine, but It does not smell like normal. Smells a little fishy (pun intended). I have my 75g quarantine up and running in case I have to transfer the fish over. Do you think there is enough bacteria on the biomedia to support 2 clowns and a coral beauty in a 75g with an AC110 HOB or should I get some bottled bacteria to add like Seachem Stability?

Last week I tried some chemiclean to get rid of the cyno, but it did not do a thing and I followed the directions exactly. Everything seemed fine afterwards as I did a 20% water change. I added new carbon to the reactor and turned it back on along with the skimmer.

 

Strong sour fishy smell is usually cyanobacteria. How long do you run your lights? try cutting back to no more then 10 hours a day and keep using chemclean as instructed.

How long has it been running and do you have a substrate? Just to be sure the water is stable. A hang on back may not move the water enough but adding a power head should be plenty if its FO for 3 fish in a 75g your not gonna spike anything.

 

Products like Microbacter7 and BioSpire from IO never hurt anything if you want to be on the safe side