New fish for 40g/cloudy water/brown algae

[jaowl]

Maybe someone can answer a question here for a newbie. I set up a 40 [acronym:27c162389b="Gallon"]gal[/acronym:27c162389b] tank last year with goldfish. they went out to the pond in the spring & now this fall need a 90 [acronym:27c162389b="Gallon"]gal[/acronym:27c162389b] tank. Anyway the 40 [acronym:27c162389b="Gallon"]gal[/acronym:27c162389b] has 5 platys & 3 home hatched goldfish that are about 6 weeks old. What other fishes could be added to this tank--corydora cats? tigar barbs?, Peppered Mollies, or clown loachs.

This small tank also looks cloudy. I resett it as underground filteration. Tonite now I notice that the uplift tubes have a brown type of algae, Is this normal.? Any help would be appreciated.

Suggestions would be appreciated Thanks Jan

[Allivymar]

Hiya Jan and welcome to Aquariumadvice

I hope you don't mind; I split off your questions as they may have been missed stuck down at the end of the other post.

When you say cloudy, what color? Whitish is usually a bacterial bloom, greenish usually means algae.

And what temps do you keep the 40g at?

[TankGirl]

The brown algae is normal, and often increasing light will get rid of it, but then you get all of the other types of algae!

The baby goldfish are going to require cooler water than the other fish in the tank, and by themselves they are going to almost be enough for your tank, if you adhere to the 10-[acronym:42a8a3e0c9="Gallon"]gal[/acronym:42a8a3e0c9] per goldfish ideal (I know they are very small now). Maybe think about what you want for this tank, and decide if you want it to be a goldfish tank or a tropicals tank. If you put the goldfish elsewhere then cory cats would be wonderful in there with your platys. Tiger barbs are really zippy and nippy so if you get those be sure and get 7 or 8 of them so they will leave the other fish alone. There are loach people who will chime in I am sure about that

The cloudy water indicates to me that you may be going through a cycle, though it could be other things. Test for ammonia, nitrIte and nitrAte and if you have any levels of the first two you have your answer. Do water changes to keep those levels as low as possible and wait it out, without adding any new fish, and once the cycle is complete your water should be clear. Then do water changes to keep nitrAte levels below 40ppm.

I hope that helps!