rule 1 know thy enemy - identify the algae and then look up what it likes - in siome cases a water change (and many of them) can in fact encourage the bloom.
rule 2 is it algae or a bacterial bloom
rule 3 how bad is it really? more often than not - these things sort themselves out in time so be patient
rule 4 a tank is a mini ecosystem and part of properly cycling a tank in terms of a balanace of everything is having an algal bloom.
Other common sense stuff includes dont over feed the piskies or the plants for that matter - reduce lighting (or even black the tank out for a couple of weeks) but otherwise treat the tank as normal (chemicals are a last resort tbh)
if its the hair type algae - the best way to get rid is to get your hands in there and pull it out -a toothbrush (your wifes will work better than your own
) is the best tool for this job - the algae hates being disturbed too often and ends up quitting.
Other options include fish that eat algae or shrimp etc.
If you want a quick fix then liquid co2 fert often does the trick if you intentionally overdose the treatment and a long term fix is to use a prduct called Aquakat Tank Clear (
www.aquakat.co.uk I think - half the price from the manufacturer than the lfs)
If the gunk is on ornaments - then take em out and boil em, bleach em, boil em, freeze em, nuke em or whatever - be a bitch to the algae but be sure the ornaments are safe again for the fish afterwards
im sure ive left stuff out but hope this helps a bit