Good Algea Eater For My Coldwater Tank

my goldfish's tank has quite a bit of algea in it. is there any fish suitable for coldwater? would be safe to add my baby pleco or ottos from my other tanks just for a few days till all or most of the algea is eaten?

Use an algae scraper.

It would depend on the temperature difference. You cant put tropical fish into really cold water.
If it was only for a couple of days and the temperature was similar then the plec would be fine.

If you want to buy one then a hillstream loach would do well in a well filtered tank or if the temp is high enough a bristlenose would work.

But to put one in permanently you would have to look at stocking levels as plecs are huge waste producers as well.

Yeah hillstream loach (sometimes sold as 'borneo sucker') can live in room temperature water and will eat some algae. Apple snails also eat algae to an extent I believe (don't quote me on that though).
To be honest though, neither of these will make much difference to the amount of algae in your tank. It's more likely that they'll make it worse in the long run. More fish equals more waste, so more nitrates to promote algal growth. To get rid of algae in the long run I would be more inclined to put some fast growing plants like vallisneria in there, make sure the substrate is kept free of detritus, perform weekly 25-30% water changes, make sure you have a really hefty filter in the tank and don't have the lights on for more than 8 or 10 hours.
Plastic wallpaper scrapers with a stanley blade in it make really *excellent* algae removal tools, provided you change the blades when they are getting blunt or rusted.

you could use one of those algae-wipers they sell in petstores that have a magnet on either side of the tank walls, but make sure that the magnet is strong enough so it will attract the wiper back to the tank wall if it falls off.
Plecos eat algae too. They do produce more waste though so I suggest using other algae-eaters.
hope that helps!!
~Caroline~

after reading this topic i doubt it have been mention but i fail to see an mention of getting Algea Wafer for feeding, if u do buy Borno Sucker or other kind of algea eater as well bristle nose

i have got a pingi pingu. He eats al the algae of the sides. He is very good.
Here is a picture of one: