Please help! (In my tank I have a large common gold fish, two small common gold fish, a black moor, corydora, algae eater, and a pleco)

[Shullzie22]

I recently about a month ago upgraded my 10gallon tank with my pretty large gold fish and pleco to a 20gallon tank and added two smaller goldfish and the tank seemed fine. I then bought a black moor from Walmart (HORRIBLE DECISION, WONT DO IT AGAIN!) placed him in the tank and a couple days later he developed white spots (ick) and infected all of my fish (cured the ick now) who have never had issues and I've had my two for about 7 years, along with the ick my tank became cloudy and is still cloudy and it seems like I've tried everything! My fish are also pooping poops that look like they're wrapped in a sausage lining and sometimes following those poops are thin white hair like things. Could this be parasites.

[Autumnsky]

That many GF need to be in a 55G and you need to ramp up the filtration, and water changes.

What are the parameters at? Ammonia, NitrIte, and NitrAte? Temp, pH?

What is the filter you have now?

Do you rinse/clean it in tap water or replace it very often?

Here is a thread to read/check on and see what a fish can look like when it is well cared for and how big they can get!
http://www.aquariumadvice.com/forums...ve-265871.html

Section here for cool water fish
Freshwater & Brackish - Coldwater, Native Fish & Ponds - Aquarium Advice - Aquarium Forum Community
Read through the getting started link in my signature asap as there are some good tidbits of info.

[Coursair]

If you want to keep Goldfish, go big. Large tank, big filter.

No pleco...they just add to the poop. And if they get startled, they can injure your GF by accident.

Rehome the poor Cory. They need groups and are tropical.

Common Goldfish do best in ponds. In a tank ? I'd go to 75g if you can. Easier to keep clean.

Commons can hit 10-12" and live over 20years. But goldfish do a majority of their growth in the first year and if you do not provide a large enough environment they will stunt and die young.

Fancies are better suited to tanks. But a 20g is barely big enough for 1. Fancies can hit 6" and live over 15yrs.

They poop a lot so need lots of filtration and water changes.

SolidGold on YouTube has some great Goldfish advice. She breeds Goldfish.

[Coursair]

Test your water with an API Master Test Kit. About $20.

[Coursair]

Common Plecos hit 12" recommended tank size 125g I believe.

If your fish aren't growing fast, that is a sign. Both Plecos and GF grow quickly.

It's great you tried to upgrade them. Think bigger

This is what your Pleco should look like with good care.