Hi Piotr, suffering this myself after a complete clean and rescape. Just waiting on some Excel to be delivered so I can hit it with the One Two punch. This has been extremely effective in allowing me to focus on the plants again instead of losing the battle. At the moment I have the staghorn pearling all day which is depressing. http://www.plantedtank.net/forums/showthread.php?t=203684
My staghorns were pearling too. I've reduced light intensity so that there's no pearling and want to see stop of expansion first. This algae really shows delayed boost from introducing more fish/CO2 problems/ stirring the substrate. Actually looks quite cool on driftwood I think
Excel arrived and I performed the one two with great success. Turned off the filters and ran my power heads. Decided to run with two tablespoons h202 per ten gallons for fifteen minutes. 50 percent water change and then a dose of 5ml excel per 10 gallons. Followed that up this morning with another dose of excel before heading to work, never bothered with that before but wanted to be sure.
Got home tonight and every ounce of staghorn is dead including the BBA. Tank looks bright and healthy again...for now. Good luck with yours.
Unfortunately I am unable to get shrimp for mine so I cannot advise however I notice that in the reference material he drops his from four tablespoons down to two as its a safer method. Flow seems to be the most important factor as is time. I run two power heads during this process and time it to the minute then perform the water change as quickly as I'm able. Perhaps if your cautious you might drop to one tablespoon per 10 gallon and follow up with excel. If confident in say three to four weeks raise this to two should the exercise not provide a reasonable result. I wouldn't want to risk shrimp if I had them so understand your caution. My care is for a Golden Ram within this aquarium so I am always very careful not to go crazy when doing things.